ext4: call ext4_forget() from ext4_free_blocks()

Add the facility for ext4_forget() to be called from
ext4_free_blocks().  This simplifies the code in a large number of
places, and centralizes most of the work of calling ext4_forget() into
a single place.

Also fix a bug in the extents migration code; it wasn't calling
ext4_forget() when releasing the indirect blocks during the
conversion.  As a result, if the system cashed during or shortly after
the extents migration, and the released indirect blocks get reused as
data blocks, the journal replay would corrupt the data blocks.  With
this new patch, fixing this bug was as simple as adding the
EXT4_FREE_BLOCKS_FORGET flags to the call to ext4_free_blocks().

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>

1 files changed, 9 insertions, 7 deletions

diff --git a/include/trace/events/ext4.h b/include/trace/events/ext4.h
index b390e1fc4a7b..74f628bfdd1b 100644
--- a/include/trace/events/ext4.h
+++ b/include/trace/events/ext4.h
@@ -650,30 +650,32 @@ TRACE_EVENT(ext4_allocate_blocks,
 
 TRACE_EVENT(ext4_free_blocks,
         TP_PROTO(struct inode *inode, __u64 block, unsigned long count,
-                        int metadata),
+                 int flags),
 
-        TP_ARGS(inode, block, count, metadata),
+        TP_ARGS(inode, block, count, flags),
 
         TP_STRUCT__entry(
                 __field(        dev_t,  dev                     )
                 __field(        ino_t,  ino                     )
+                __field(      umode_t, mode                     )
                 __field(        __u64,  block                   )
                 __field(        unsigned long,  count           )
-                __field(        int,    metadata                )
-
+                __field(         int,   flags                   )
         ),
 
         TP_fast_assign(
                 __entry->dev            = inode->i_sb->s_dev;
                 __entry->ino            = inode->i_ino;
+                __entry->mode           = inode->i_mode;
                 __entry->block          = block;
                 __entry->count          = count;
-                __entry->metadata       = metadata;
+                __entry->flags          = flags;
         ),
 
-        TP_printk("dev %s ino %lu block %llu count %lu metadata %d",
+        TP_printk("dev %s ino %lu mode 0%o block %llu count %lu flags %d",
                   jbd2_dev_to_name(__entry->dev), (unsigned long) __entry->ino,
-                  __entry->block, __entry->count, __entry->metadata)
+                  __entry->mode, __entry->block, __entry->count,
+                  __entry->flags)
 );
 
 TRACE_EVENT(ext4_sync_file,