ocfs2: Wrap inode block reads in a dedicated function.

The ocfs2 code currently reads inodes off disk with a simple
ocfs2_read_block() call.  Each place that does this has a different set
of sanity checks it performs.  Some check only the signature.  A couple
validate the block number (the block read vs di->i_blkno).  A couple
others check for VALID_FL.  Only one place validates i_fs_generation.  A
couple check nothing.  Even when an error is found, they don't all do
the same thing.

We wrap inode reading into ocfs2_read_inode_block().  This will validate
all the above fields, going readonly if they are invalid (they never
should be).  ocfs2_read_inode_block_full() is provided for the places
that want to pass read_block flags.  Every caller is passing a struct
inode with a valid ip_blkno, so we don't need a separate blkno argument
either.

We will remove the validation checks from the rest of the code in a
later commit, as they are no longer necessary.

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

1 files changed, 4 insertions, 8 deletions

diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c
index 6e6cc0a2e5f..9f2a7f75d1b 100644
--- a/fs/ocfs2/dlmglue.c
+++ b/fs/ocfs2/dlmglue.c
@@ -2024,7 +2024,7 @@ static int ocfs2_inode_lock_update(struct inode *inode,
 	} else {
 		/* Boo, we have to go to disk. */
 		/* read bh, cast, ocfs2_refresh_inode */
-		status = ocfs2_read_block(inode, oi->ip_blkno, bh);
+		status = ocfs2_read_inode_block(inode, bh);
 		if (status < 0) {
 			mlog_errno(status);
 			goto bail_refresh;
@@ -2032,18 +2032,14 @@ static int ocfs2_inode_lock_update(struct inode *inode,
 		fe = (struct ocfs2_dinode *) (*bh)->b_data;
 
 		/* This is a good chance to make sure we're not
-		 * locking an invalid object.
+		 * locking an invalid object.  ocfs2_read_inode_block()
+		 * already checked that the inode block is sane.
 		 *
 		 * We bug on a stale inode here because we checked
 		 * above whether it was wiped from disk. The wiping
 		 * node provides a guarantee that we receive that
 		 * message and can mark the inode before dropping any
 		 * locks associated with it. */
-		if (!OCFS2_IS_VALID_DINODE(fe)) {
-			OCFS2_RO_ON_INVALID_DINODE(inode->i_sb, fe);
-			status = -EIO;
-			goto bail_refresh;
-		}
 		mlog_bug_on_msg(inode->i_generation !=
 				le32_to_cpu(fe->i_generation),
 				"Invalid dinode %llu disk generation: %u "
@@ -2085,7 +2081,7 @@ static int ocfs2_assign_bh(struct inode *inode,
 		return 0;
 	}
 
-	status = ocfs2_read_block(inode, OCFS2_I(inode)->ip_blkno, ret_bh);
+	status = ocfs2_read_inode_block(inode, ret_bh);
 	if (status < 0)
 		mlog_errno(status);