ocfs2: Use buckets in ocfs2_xattr_bucket_find().

Change the ocfs2_xattr_bucket_find() function to use ocfs2_xattr_bucket
as its abstraction.  This makes for more efficient reads, as buckets are
linear blocks, and also has improved caching characteristics.  It also
reads better.

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

1 files changed, 31 insertions, 58 deletions

diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c
index 766494ed6e11..46986c635eb8 100644
--- a/fs/ocfs2/xattr.c
+++ b/fs/ocfs2/xattr.c
@@ -2248,7 +2248,7 @@ typedef int (xattr_bucket_func)(struct inode *inode,
                                 void *para);
 
 static int ocfs2_find_xe_in_bucket(struct inode *inode,
-                                   struct buffer_head *header_bh,
+                                   struct ocfs2_xattr_bucket *bucket,
                                    int name_index,
                                    const char *name,
                                    u32 name_hash,
@@ -2256,11 +2256,9 @@ static int ocfs2_find_xe_in_bucket(struct inode *inode,
                                    int *found)
 {
         int i, ret = 0, cmp = 1, block_off, new_offset;
-        struct ocfs2_xattr_header *xh =
-                        (struct ocfs2_xattr_header *)header_bh->b_data;
+        struct ocfs2_xattr_header *xh = bucket_xh(bucket);
         size_t name_len = strlen(name);
         struct ocfs2_xattr_entry *xe = NULL;
-        struct buffer_head *name_bh = NULL;
         char *xe_name;
 
         /*
@@ -2291,19 +2289,8 @@ static int ocfs2_find_xe_in_bucket(struct inode *inode,
                         break;
                 }
 
-                ret = ocfs2_read_block(inode, header_bh->b_blocknr + block_off,
-                                       &name_bh);
-                if (ret) {
-                        mlog_errno(ret);
-                        break;
-                }
-                xe_name = name_bh->b_data + new_offset;
-
-                cmp = memcmp(name, xe_name, name_len);
-                brelse(name_bh);
-                name_bh = NULL;
-
-                if (cmp == 0) {
+                xe_name = bucket_block(bucket, block_off) + new_offset;
+                if (!memcmp(name, xe_name, name_len)) {
                         *xe_index = i;
                         *found = 1;
                         ret = 0;
@@ -2333,39 +2320,42 @@ static int ocfs2_xattr_bucket_find(struct inode *inode,
                                    struct ocfs2_xattr_search *xs)
 {
         int ret, found = 0;
-        struct buffer_head *bh = NULL;
-        struct buffer_head *lower_bh = NULL;
         struct ocfs2_xattr_header *xh = NULL;
         struct ocfs2_xattr_entry *xe = NULL;
         u16 index = 0;
         u16 blk_per_bucket = ocfs2_blocks_per_xattr_bucket(inode->i_sb);
         int low_bucket = 0, bucket, high_bucket;
+        struct ocfs2_xattr_bucket *search;
         u32 last_hash;
-        u64 blkno;
+        u64 blkno, lower_blkno = 0;
 
-        ret = ocfs2_read_block(inode, p_blkno, &bh);
+        search = ocfs2_xattr_bucket_new(inode);
+        if (!search) {
+                ret = -ENOMEM;
+                mlog_errno(ret);
+                goto out;
+        }
+
+        ret = ocfs2_read_xattr_bucket(search, p_blkno);
         if (ret) {
                 mlog_errno(ret);
                 goto out;
         }
 
-        xh = (struct ocfs2_xattr_header *)bh->b_data;
+        xh = bucket_xh(search);
         high_bucket = le16_to_cpu(xh->xh_num_buckets) - 1;
-
         while (low_bucket <= high_bucket) {
-                brelse(bh);
-                bh = NULL;
-                bucket = (low_bucket + high_bucket) / 2;
+                ocfs2_xattr_bucket_relse(search);
 
+                bucket = (low_bucket + high_bucket) / 2;
                 blkno = p_blkno + bucket * blk_per_bucket;
-
-                ret = ocfs2_read_block(inode, blkno, &bh);
+                ret = ocfs2_read_xattr_bucket(search, blkno);
                 if (ret) {
                         mlog_errno(ret);
                         goto out;
                 }
 
-                xh = (struct ocfs2_xattr_header *)bh->b_data;
+                xh = bucket_xh(search);
                 xe = &xh->xh_entries[0];
                 if (name_hash < le32_to_cpu(xe->xe_name_hash)) {
                         high_bucket = bucket - 1;
@@ -2382,10 +2372,8 @@ static int ocfs2_xattr_bucket_find(struct inode *inode,
 
                 last_hash = le32_to_cpu(xe->xe_name_hash);
 
-                /* record lower_bh which may be the insert place. */
-                brelse(lower_bh);
-                lower_bh = bh;
-                bh = NULL;
+                /* record lower_blkno which may be the insert place. */
+                lower_blkno = blkno;
 
                 if (name_hash > le32_to_cpu(xe->xe_name_hash)) {
                         low_bucket = bucket + 1;
@@ -2393,7 +2381,7 @@ static int ocfs2_xattr_bucket_find(struct inode *inode,
                 }
 
                 /* the searched xattr should reside in this bucket if exists. */
-                ret = ocfs2_find_xe_in_bucket(inode, lower_bh,
+                ret = ocfs2_find_xe_in_bucket(inode, search,
                                               name_index, name, name_hash,
                                               &index, &found);
                 if (ret) {
@@ -2408,35 +2396,21 @@ static int ocfs2_xattr_bucket_find(struct inode *inode,
          * When the xattr's hash value is in the gap of 2 buckets, we will
          * always set it to the previous bucket.
          */
-        if (!lower_bh) {
-                /*
-                 * We can't find any bucket whose first name_hash is less
-                 * than the find name_hash.
-                 */
-                BUG_ON(bh->b_blocknr != p_blkno);
-                lower_bh = bh;
-                bh = NULL;
+        if (!lower_blkno)
+                lower_blkno = p_blkno;
+
+        /* This should be in cache - we just read it during the search */
+        ret = ocfs2_read_xattr_bucket(xs->bucket, lower_blkno);
+        if (ret) {
+                mlog_errno(ret);
+                goto out;
         }
-        xs->bucket->bu_bhs[0] = lower_bh;
-        lower_bh = NULL;
 
         xs->header = bucket_xh(xs->bucket);
         xs->base = bucket_block(xs->bucket, 0);
         xs->end = xs->base + inode->i_sb->s_blocksize;
 
         if (found) {
-                /*
-                 * If we have found the xattr enty, read all the blocks in
-                 * this bucket.
-                 */
-                ret = ocfs2_read_blocks(inode, bucket_blkno(xs->bucket) + 1,
-                                        blk_per_bucket - 1, &xs->bucket->bu_bhs[1],
-                                        0);
-                if (ret) {
-                        mlog_errno(ret);
-                        goto out;
-                }
-
                 xs->here = &xs->header->xh_entries[index];
                 mlog(0, "find xattr %s in bucket %llu, entry = %u\n", name,
                      (unsigned long long)bucket_blkno(xs->bucket), index);
@@ -2444,8 +2418,7 @@ static int ocfs2_xattr_bucket_find(struct inode *inode,
                 ret = -ENODATA;
 
 out:
-        brelse(bh);
-        brelse(lower_bh);
+        ocfs2_xattr_bucket_free(search);
         return ret;
 }