ocfs2: Convenient access to an xattr bucket's header.

The xattr code often wants to access the ocfs2_xattr_header at the start
of an bucket.  Rather than walk the pointer chains, let's just create
another nice macro.  As a side benefit, we can get rid of the mostly
spurious ->bu_xh element on the bucket structure.  The idea is ripped
from the ocfs2_path code.

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

diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c
index 8594df3..1b77302 100644 (file)
--- a/fs/ocfs2/xattr.c
+++ b/fs/ocfs2/xattr.c
@@ -62,7 +62,6 @@ struct ocfs2_xattr_def_value_root {
 
 struct ocfs2_xattr_bucket {
        struct buffer_head *bu_bhs[OCFS2_XATTR_MAX_BLOCKS_PER_BUCKET];
-       struct ocfs2_xattr_header *bu_xh;
 };
 
 #define OCFS2_XATTR_ROOT_SIZE  (sizeof(struct ocfs2_xattr_def_value_root))
@@ -156,6 +155,7 @@ static inline u16 ocfs2_xattr_max_xe_in_bucket(struct super_block *sb)
 
 #define bucket_blkno(_b) ((_b)->bu_bhs[0]->b_blocknr)
 #define bucket_block(_b, _n) ((_b)->bu_bhs[(_n)]->b_data)
+#define bucket_xh(_b) ((struct ocfs2_xattr_header *)bucket_block((_b), 0))
 
 static inline const char *ocfs2_xattr_prefix(int name_index)
 {
@@ -798,7 +798,7 @@ static int ocfs2_xattr_block_get(struct inode *inode,
 
                if (le16_to_cpu(xb->xb_flags) & OCFS2_XATTR_INDEXED) {
                        ret = ocfs2_xattr_bucket_get_name_value(inode,
-                                                               xs->bucket.bu_xh,
+                                                               bucket_xh(&xs->bucket),
                                                                i,
                                                                &block_off,
                                                                &name_offset);
@@ -2280,11 +2280,9 @@ static int ocfs2_xattr_bucket_find(struct inode *inode,
                bh = NULL;
        }
        xs->bucket.bu_bhs[0] = lower_bh;
-       xs->bucket.bu_xh = (struct ocfs2_xattr_header *)
-                                       bucket_block(&xs->bucket, 0);
        lower_bh = NULL;
 
-       xs->header = xs->bucket.bu_xh;
+       xs->header = bucket_xh(&xs->bucket);
        xs->base = bucket_block(&xs->bucket, 0);
        xs->end = xs->base + inode->i_sb->s_blocksize;
 
@@ -2379,17 +2377,16 @@ static int ocfs2_iterate_xattr_buckets(struct inode *inode,
                        goto out;
                }
 
-               bucket.bu_xh = (struct ocfs2_xattr_header *)bucket_block(&bucket, 0);
                /*
                 * The real bucket num in this series of blocks is stored
                 * in the 1st bucket.
                 */
                if (i == 0)
-                       num_buckets = le16_to_cpu(bucket.bu_xh->xh_num_buckets);
+                       num_buckets = le16_to_cpu(bucket_xh(&bucket)->xh_num_buckets);
 
                mlog(0, "iterating xattr bucket %llu, first hash %u\n",
                     (unsigned long long)blkno,
-                    le32_to_cpu(bucket.bu_xh->xh_entries[0].xe_name_hash));
+                    le32_to_cpu(bucket_xh(&bucket)->xh_entries[0].xe_name_hash));
                if (func) {
                        ret = func(inode, &bucket, para);
                        if (ret) {
@@ -2444,14 +2441,14 @@ static int ocfs2_list_xattr_bucket(struct inode *inode,
        int i, block_off, new_offset;
        const char *prefix, *name;
 
-       for (i = 0 ; i < le16_to_cpu(bucket->bu_xh->xh_count); i++) {
-               struct ocfs2_xattr_entry *entry = &bucket->bu_xh->xh_entries[i];
+       for (i = 0 ; i < le16_to_cpu(bucket_xh(bucket)->xh_count); i++) {
+               struct ocfs2_xattr_entry *entry = &bucket_xh(bucket)->xh_entries[i];
                type = ocfs2_xattr_get_type(entry);
                prefix = ocfs2_xattr_prefix(type);
 
                if (prefix) {
                        ret = ocfs2_xattr_bucket_get_name_value(inode,
-                                                               bucket->bu_xh,
+                                                               bucket_xh(bucket),
                                                                i,
                                                                &block_off,
                                                                &new_offset);
@@ -2631,8 +2628,7 @@ static int ocfs2_xattr_update_xattr_search(struct inode *inode,
 
        xs->bucket.bu_bhs[0] = new_bh;
        get_bh(new_bh);
-       xs->bucket.bu_xh = (struct ocfs2_xattr_header *)bucket_block(&xs->bucket, 0);
-       xs->header = xs->bucket.bu_xh;
+       xs->header = bucket_xh(&xs->bucket);
 
        xs->base = new_bh->b_data;
        xs->end = xs->base + inode->i_sb->s_blocksize;
@@ -4398,7 +4394,7 @@ static void ocfs2_xattr_bucket_remove_xs(struct inode *inode,
                                         struct ocfs2_xattr_search *xs)
 {
        handle_t *handle = NULL;
-       struct ocfs2_xattr_header *xh = xs->bucket.bu_xh;
+       struct ocfs2_xattr_header *xh = bucket_xh(&xs->bucket);
        struct ocfs2_xattr_entry *last = &xh->xh_entries[
                                                le16_to_cpu(xh->xh_count) - 1];
        int ret = 0;
@@ -4533,7 +4529,7 @@ static int ocfs2_check_xattr_bucket_collision(struct inode *inode,
                                              struct ocfs2_xattr_bucket *bucket,
                                              const char *name)
 {
-       struct ocfs2_xattr_header *xh = bucket->bu_xh;
+       struct ocfs2_xattr_header *xh = bucket_xh(bucket);
        u32 name_hash = ocfs2_xattr_name_hash(inode, name, strlen(name));
 
        if (name_hash != le32_to_cpu(xh->xh_entries[0].xe_name_hash))
@@ -4703,7 +4699,7 @@ static int ocfs2_delete_xattr_in_bucket(struct inode *inode,
                                        void *para)
 {
        int ret = 0;
-       struct ocfs2_xattr_header *xh = bucket->bu_xh;
+       struct ocfs2_xattr_header *xh = bucket_xh(bucket);
        u16 i;
        struct ocfs2_xattr_entry *xe;