ocfs2: Validate metadata only when it's read from disk.
Add an optional validation hook to ocfs2_read_blocks(). Now the
validation function is only called when a block was actually read off of
disk. It is not called when the buffer was in cache.
We add a buffer state bit BH_NeedsValidate to flag these buffers. It
must always be one higher than the last JBD2 buffer state bit.
The dinode, dirblock, extent_block, and xattr_block validators are
lifted to this scheme directly. The group_descriptor validator needs to
be split into two pieces. The first part only needs the gd buffer and
is passed to ocfs2_read_block(). The second part requires the dinode as
well, and is called every time. It's only 3 compares, so it's tiny.
This also allows us to clean up the non-fatal gd check used by resize.c.
It now has no magic argument.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
diff --git a/fs/ocfs2/buffer_head_io.h b/fs/ocfs2/buffer_head_io.h
index 75e1dcb..c75d682 100644
--- a/fs/ocfs2/buffer_head_io.h
+++ b/fs/ocfs2/buffer_head_io.h
@@ -31,21 +31,24 @@
void ocfs2_end_buffer_io_sync(struct buffer_head *bh,
int uptodate);
-static inline int ocfs2_read_block(struct inode *inode,
- u64 off,
- struct buffer_head **bh);
-
int ocfs2_write_block(struct ocfs2_super *osb,
struct buffer_head *bh,
struct inode *inode);
-int ocfs2_read_blocks(struct inode *inode,
- u64 block,
- int nr,
- struct buffer_head *bhs[],
- int flags);
int ocfs2_read_blocks_sync(struct ocfs2_super *osb, u64 block,
unsigned int nr, struct buffer_head *bhs[]);
+/*
+ * If not NULL, validate() will be called on a buffer that is freshly
+ * read from disk. It will not be called if the buffer was in cache.
+ * Note that if validate() is being used for this buffer, it needs to
+ * be set even for a READAHEAD call, as it marks the buffer for later
+ * validation.
+ */
+int ocfs2_read_blocks(struct inode *inode, u64 block, int nr,
+ struct buffer_head *bhs[], int flags,
+ int (*validate)(struct super_block *sb,
+ struct buffer_head *bh));
+
int ocfs2_write_super_or_backup(struct ocfs2_super *osb,
struct buffer_head *bh);
@@ -53,7 +56,9 @@
#define OCFS2_BH_READAHEAD 8
static inline int ocfs2_read_block(struct inode *inode, u64 off,
- struct buffer_head **bh)
+ struct buffer_head **bh,
+ int (*validate)(struct super_block *sb,
+ struct buffer_head *bh))
{
int status = 0;
@@ -63,7 +68,7 @@
goto bail;
}
- status = ocfs2_read_blocks(inode, off, 1, bh, 0);
+ status = ocfs2_read_blocks(inode, off, 1, bh, 0, validate);
bail:
return status;