Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (43 commits)
  ext4: fix a BUG in mb_mark_used during trim.
  ext4: unused variables cleanup in fs/ext4/extents.c
  ext4: remove redundant set_buffer_mapped() in ext4_da_get_block_prep()
  ext4: add more tracepoints and use dev_t in the trace buffer
  ext4: don't kfree uninitialized s_group_info members
  ext4: add missing space in printk's in __ext4_grp_locked_error()
  ext4: add FITRIM to compat_ioctl.
  ext4: handle errors in ext4_clear_blocks()
  ext4: unify the ext4_handle_release_buffer() api
  ext4: handle errors in ext4_rename
  jbd2: add COW fields to struct jbd2_journal_handle
  jbd2: add the b_cow_tid field to journal_head struct
  ext4: Initialize fsync transaction ids in ext4_new_inode()
  ext4: Use single thread to perform DIO unwritten convertion
  ext4: optimize ext4_bio_write_page() when no extent conversion is needed
  ext4: skip orphan cleanup if fs has unknown ROCOMPAT features
  ext4: use the nblocks arg to ext4_truncate_restart_trans()
  ext4: fix missing iput of root inode for some mount error paths
  ext4: make FIEMAP and delayed allocation play well together
  ext4: suppress verbose debugging information if malloc-debug is off
  ...

Fi up conflicts in fs/ext4/super.c due to workqueue changes

2 files changed, 32 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
 };
 
 
diff --git a/include/linux/journal-head.h b/include/linux/journal-head.h
index 525aac3c97df..44e95d0a721f 100644
--- a/include/linux/journal-head.h
+++ b/include/linux/journal-head.h
@@ -41,6 +41,13 @@ struct journal_head {
         unsigned b_modified;
 
         /*
+         * This feild tracks the last transaction id in which this buffer
+         * has been cowed
+         * [jbd_lock_bh_state()]
+         */
+        unsigned b_cow_tid;
+
+        /*
          * Copy of the buffer data frozen for writing to the log.
          * [jbd_lock_bh_state()]
          */