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authorJoel Becker <joel.becker@oracle.com>2008-11-13 14:49:19 -0800
committerMark Fasheh <mfasheh@suse.com>2009-01-05 08:36:53 -0800
commit970e4936d7d15f35d00fd15a14f5343ba78b2fc8 (patch)
tree92057c7deab6b9d8e5c3889d6a354b5989a3b68d /fs/ocfs2/buffer_head_io.c
parent4ae1d69bedc8d174cb8a558694607e013157cde1 (diff)
downloadlinux-970e4936d7d15f35d00fd15a14f5343ba78b2fc8.tar.bz2
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>
Diffstat (limited to 'fs/ocfs2/buffer_head_io.c')
-rw-r--r--fs/ocfs2/buffer_head_io.c33
1 files changed, 32 insertions, 1 deletions
diff --git a/fs/ocfs2/buffer_head_io.c b/fs/ocfs2/buffer_head_io.c
index 3a178ec48d7c..0e9eed0c223f 100644
--- a/fs/ocfs2/buffer_head_io.c
+++ b/fs/ocfs2/buffer_head_io.c
@@ -39,6 +39,19 @@
#include "buffer_head_io.h"
+/*
+ * Bits on bh->b_state used by ocfs2.
+ *
+ * These MUST be after the JBD2 bits. Currently BH_Unshadow is the last
+ * JBD2 bit.
+ */
+enum ocfs2_state_bits {
+ BH_NeedsValidate = BH_Unshadow + 1,
+};
+
+/* Expand the magic b_state functions */
+BUFFER_FNS(NeedsValidate, needs_validate);
+
int ocfs2_write_block(struct ocfs2_super *osb, struct buffer_head *bh,
struct inode *inode)
{
@@ -166,7 +179,9 @@ bail:
}
int ocfs2_read_blocks(struct inode *inode, u64 block, int nr,
- struct buffer_head *bhs[], int flags)
+ struct buffer_head *bhs[], int flags,
+ int (*validate)(struct super_block *sb,
+ struct buffer_head *bh))
{
int status = 0;
int i, ignore_cache = 0;
@@ -298,6 +313,8 @@ int ocfs2_read_blocks(struct inode *inode, u64 block, int nr,
clear_buffer_uptodate(bh);
get_bh(bh); /* for end_buffer_read_sync() */
+ if (validate)
+ set_buffer_needs_validate(bh);
bh->b_end_io = end_buffer_read_sync;
submit_bh(READ, bh);
continue;
@@ -328,6 +345,20 @@ int ocfs2_read_blocks(struct inode *inode, u64 block, int nr,
bhs[i] = NULL;
continue;
}
+
+ if (buffer_needs_validate(bh)) {
+ /* We never set NeedsValidate if the
+ * buffer was held by the journal, so
+ * that better not have changed */
+ BUG_ON(buffer_jbd(bh));
+ clear_buffer_needs_validate(bh);
+ status = validate(inode->i_sb, bh);
+ if (status) {
+ put_bh(bh);
+ bhs[i] = NULL;
+ continue;
+ }
+ }
}
/* Always set the buffer in the cache, even if it was