ocfs2: Checksum and ECC for directory blocks.

Use the db_check field of ocfs2_dir_block_trailer to crc/ecc the
dirblocks.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>

4 files changed, 67 insertions, 5 deletions

diff --git a/fs/ocfs2/dir.c b/fs/ocfs2/dir.c
index 1efd0ab680cf..f2c4098cf337 100644
--- a/fs/ocfs2/dir.c
+++ b/fs/ocfs2/dir.c
@@ -48,6 +48,7 @@
 #include "ocfs2.h"
 
 #include "alloc.h"
+#include "blockcheck.h"
 #include "dir.h"
 #include "dlmglue.h"
 #include "extent_map.h"
@@ -107,6 +108,17 @@ static inline unsigned int ocfs2_dir_trailer_blk_off(struct super_block *sb)
 
 #define ocfs2_trailer_from_bh(_bh, _sb) ((struct ocfs2_dir_block_trailer *) ((_bh)->b_data + ocfs2_dir_trailer_blk_off((_sb))))
 
+/* XXX ocfs2_block_dqtrailer() is similar but not quite - can we make
+ * them more consistent? */
+struct ocfs2_dir_block_trailer *ocfs2_dir_trailer_from_size(int blocksize,
+                                                            void *data)
+{
+        char *p = data;
+
+        p += blocksize - sizeof(struct ocfs2_dir_block_trailer);
+        return (struct ocfs2_dir_block_trailer *)p;
+}
+
 /*
  * XXX: This is executed once on every dirent. We should consider optimizing
  * it.
@@ -268,14 +280,35 @@ out:
 static int ocfs2_validate_dir_block(struct super_block *sb,
                                     struct buffer_head *bh)
 {
+        int rc;
+        struct ocfs2_dir_block_trailer *trailer =
+                ocfs2_trailer_from_bh(bh, sb);
+
+
         /*
-         * Nothing yet.  We don't validate dirents here, that's handled
+         * We don't validate dirents here, that's handled
          * in-place when the code walks them.
          */
         mlog(0, "Validating dirblock %llu\n",
              (unsigned long long)bh->b_blocknr);
 
-        return 0;
+        BUG_ON(!buffer_uptodate(bh));
+
+        /*
+         * If the ecc fails, we return the error but otherwise
+         * leave the filesystem running.  We know any error is
+         * local to this block.
+         *
+         * Note that we are safe to call this even if the directory
+         * doesn't have a trailer.  Filesystems without metaecc will do
+         * nothing, and filesystems with it will have one.
+         */
+        rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &trailer->db_check);
+        if (rc)
+                mlog(ML_ERROR, "Checksum failed for dinode %llu\n",
+                     (unsigned long long)bh->b_blocknr);
+
+        return rc;
 }
 
 /*
diff --git a/fs/ocfs2/dir.h b/fs/ocfs2/dir.h
index ce48b9080d87..c511e2e18e9f 100644
--- a/fs/ocfs2/dir.h
+++ b/fs/ocfs2/dir.h
@@ -83,4 +83,6 @@ int ocfs2_fill_new_dir(struct ocfs2_super *osb,
                        struct buffer_head *fe_bh,
                        struct ocfs2_alloc_context *data_ac);
 
+struct ocfs2_dir_block_trailer *ocfs2_dir_trailer_from_size(int blocksize,
+                                                            void *data);
 #endif /* OCFS2_DIR_H */
diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c
index 3b54dba0f74b..57d7d25a2b9a 100644
--- a/fs/ocfs2/journal.c
+++ b/fs/ocfs2/journal.c
@@ -415,6 +415,26 @@ static void ocfs2_dq_commit_trigger(struct jbd2_buffer_trigger_type *triggers,
         ocfs2_block_check_compute(data, size, &dqt->dq_check);
 }
 
+/*
+ * Directory blocks also have their own trigger because the
+ * struct ocfs2_block_check offset depends on the blocksize.
+ */
+static void ocfs2_db_commit_trigger(struct jbd2_buffer_trigger_type *triggers,
+                                 struct buffer_head *bh,
+                                 void *data, size_t size)
+{
+        struct ocfs2_dir_block_trailer *trailer =
+                ocfs2_dir_trailer_from_size(size, data);
+
+        /*
+         * We aren't guaranteed to have the superblock here, so we
+         * must unconditionally compute the ecc data.
+         * __ocfs2_journal_access() will only set the triggers if
+         * metaecc is enabled.
+         */
+        ocfs2_block_check_compute(data, size, &trailer->db_check);
+}
+
 static void ocfs2_abort_trigger(struct jbd2_buffer_trigger_type *triggers,
                                 struct buffer_head *bh)
 {
@@ -454,6 +474,13 @@ static struct ocfs2_triggers gd_triggers = {
         .ot_offset      = offsetof(struct ocfs2_group_desc, bg_check),
 };
 
+static struct ocfs2_triggers db_triggers = {
+        .ot_triggers = {
+                .t_commit = ocfs2_db_commit_trigger,
+                .t_abort = ocfs2_abort_trigger,
+        },
+};
+
 static struct ocfs2_triggers xb_triggers = {
         .ot_triggers = {
                 .t_commit = ocfs2_commit_trigger,
@@ -555,8 +582,8 @@ int ocfs2_journal_access_gd(handle_t *handle, struct inode *inode,
 int ocfs2_journal_access_db(handle_t *handle, struct inode *inode,
                             struct buffer_head *bh, int type)
 {
-        /* Right now, nothing for dirblocks */
-        return __ocfs2_journal_access(handle, inode, bh, NULL, type);
+        return __ocfs2_journal_access(handle, inode, bh, &db_triggers,
+                                      type);
 }
 
 int ocfs2_journal_access_xb(handle_t *handle, struct inode *inode,
diff --git a/fs/ocfs2/ocfs2_fs.h b/fs/ocfs2/ocfs2_fs.h
index af0013b9c17f..698ef3d27121 100644
--- a/fs/ocfs2/ocfs2_fs.h
+++ b/fs/ocfs2/ocfs2_fs.h
@@ -776,7 +776,7 @@ struct ocfs2_dir_block_trailer {
 /*20*/  __le64          db_blkno;               /* Offset on disk, in blocks */
         __le64          db_parent_dinode;       /* dinode which owns me, in
                                                    blocks */
-/*30*/  __le64          db_check;               /* Error checking */
+/*30*/  struct ocfs2_block_check db_check;      /* Error checking */
 /*40*/
 };