diff options
| -rw-r--r-- | fs/ocfs2/xattr.c | 144 |
1 files changed, 115 insertions, 29 deletions
diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c index a371c01942b..f3ea7efb48c 100644 --- a/fs/ocfs2/xattr.c +++ b/fs/ocfs2/xattr.c @@ -3110,25 +3110,73 @@ static int ocfs2_read_xattr_bucket(struct inode *inode, } /* - * Move half num of the xattrs in old bucket(blk) to new bucket(new_blk). + * Find the suitable pos when we divide a bucket into 2. + * We have to make sure the xattrs with the same hash value exist + * in the same bucket. + * + * If this ocfs2_xattr_header covers more than one hash value, find a + * place where the hash value changes. Try to find the most even split. + * The most common case is that all entries have different hash values, + * and the first check we make will find a place to split. + */ +static int ocfs2_xattr_find_divide_pos(struct ocfs2_xattr_header *xh) +{ + struct ocfs2_xattr_entry *entries = xh->xh_entries; + int count = le16_to_cpu(xh->xh_count); + int delta, middle = count / 2; + + /* + * We start at the middle. Each step gets farther away in both + * directions. We therefore hit the change in hash value + * nearest to the middle. Note that this loop does not execute for + * count < 2. + */ + for (delta = 0; delta < middle; delta++) { + /* Let's check delta earlier than middle */ + if (cmp_xe(&entries[middle - delta - 1], + &entries[middle - delta])) + return middle - delta; + + /* For even counts, don't walk off the end */ + if ((middle + delta + 1) == count) + continue; + + /* Now try delta past middle */ + if (cmp_xe(&entries[middle + delta], + &entries[middle + delta + 1])) + return middle + delta + 1; + } + + /* Every entry had the same hash */ + return count; +} + +/* + * Move some xattrs in old bucket(blk) to new bucket(new_blk). * first_hash will record the 1st hash of the new bucket. + * + * Normally half of the xattrs will be moved. But we have to make + * sure that the xattrs with the same hash value are stored in the + * same bucket. If all the xattrs in this bucket have the same hash + * value, the new bucket will be initialized as an empty one and the + * first_hash will be initialized as (hash_value+1). */ -static int ocfs2_half_xattr_bucket(struct inode *inode, - handle_t *handle, - u64 blk, - u64 new_blk, - u32 *first_hash, - int new_bucket_head) +static int ocfs2_divide_xattr_bucket(struct inode *inode, + handle_t *handle, + u64 blk, + u64 new_blk, + u32 *first_hash, + int new_bucket_head) { int ret, i; - u16 count, start, len, name_value_len, xe_len, name_offset; + int count, start, len, name_value_len = 0, xe_len, name_offset = 0; u16 blk_per_bucket = ocfs2_blocks_per_xattr_bucket(inode->i_sb); struct buffer_head **s_bhs, **t_bhs = NULL; struct ocfs2_xattr_header *xh; struct ocfs2_xattr_entry *xe; int blocksize = inode->i_sb->s_blocksize; - mlog(0, "move half of xattrs from bucket %llu to %llu\n", + mlog(0, "move some of xattrs from bucket %llu to %llu\n", blk, new_blk); s_bhs = kcalloc(blk_per_bucket, sizeof(struct buffer_head *), GFP_NOFS); @@ -3171,14 +3219,35 @@ static int ocfs2_half_xattr_bucket(struct inode *inode, } } + xh = (struct ocfs2_xattr_header *)s_bhs[0]->b_data; + count = le16_to_cpu(xh->xh_count); + start = ocfs2_xattr_find_divide_pos(xh); + + if (start == count) { + xe = &xh->xh_entries[start-1]; + + /* + * initialized a new empty bucket here. + * The hash value is set as one larger than + * that of the last entry in the previous bucket. + */ + for (i = 0; i < blk_per_bucket; i++) + memset(t_bhs[i]->b_data, 0, blocksize); + + xh = (struct ocfs2_xattr_header *)t_bhs[0]->b_data; + xh->xh_free_start = cpu_to_le16(blocksize); + xh->xh_entries[0].xe_name_hash = xe->xe_name_hash; + le32_add_cpu(&xh->xh_entries[0].xe_name_hash, 1); + + goto set_num_buckets; + } + /* copy the whole bucket to the new first. */ for (i = 0; i < blk_per_bucket; i++) memcpy(t_bhs[i]->b_data, s_bhs[i]->b_data, blocksize); /* update the new bucket. */ xh = (struct ocfs2_xattr_header *)t_bhs[0]->b_data; - count = le16_to_cpu(xh->xh_count); - start = count / 2; /* * Calculate the total name/value len and xh_free_start for @@ -3235,6 +3304,7 @@ static int ocfs2_half_xattr_bucket(struct inode *inode, xh->xh_free_start = xe->xe_name_offset; } +set_num_buckets: /* set xh->xh_num_buckets for the new xh. */ if (new_bucket_head) xh->xh_num_buckets = cpu_to_le16(1); @@ -3252,9 +3322,13 @@ static int ocfs2_half_xattr_bucket(struct inode *inode, *first_hash = le32_to_cpu(xh->xh_entries[0].xe_name_hash); /* - * Now only update the 1st block of the old bucket. - * Please note that the entry has been sorted already above. + * Now only update the 1st block of the old bucket. If we + * just added a new empty bucket, there is no need to modify + * it. */ + if (start == count) + goto out; + xh = (struct ocfs2_xattr_header *)s_bhs[0]->b_data; memset(&xh->xh_entries[start], 0, sizeof(struct ocfs2_xattr_entry) * (count - start)); @@ -3439,15 +3513,15 @@ out: } /* - * Move half of the xattrs in this cluster to the new cluster. + * Move some xattrs in this cluster to the new cluster. * This function should only be called when bucket size == cluster size. * Otherwise ocfs2_mv_xattr_bucket_cross_cluster should be used instead. */ -static int ocfs2_half_xattr_cluster(struct inode *inode, - handle_t *handle, - u64 prev_blk, - u64 new_blk, - u32 *first_hash) +static int ocfs2_divide_xattr_cluster(struct inode *inode, + handle_t *handle, + u64 prev_blk, + u64 new_blk, + u32 *first_hash) { u16 blk_per_bucket = ocfs2_blocks_per_xattr_bucket(inode->i_sb); int ret, credits = 2 * blk_per_bucket; @@ -3461,8 +3535,8 @@ static int ocfs2_half_xattr_cluster(struct inode *inode, } /* Move half of the xattr in start_blk to the next bucket. */ - return ocfs2_half_xattr_bucket(inode, handle, prev_blk, - new_blk, first_hash, 1); + return ocfs2_divide_xattr_bucket(inode, handle, prev_blk, + new_blk, first_hash, 1); } /* @@ -3524,9 +3598,9 @@ static int ocfs2_adjust_xattr_cross_cluster(struct inode *inode, last_blk, new_blk, v_start); else { - ret = ocfs2_half_xattr_cluster(inode, handle, - last_blk, new_blk, - v_start); + ret = ocfs2_divide_xattr_cluster(inode, handle, + last_blk, new_blk, + v_start); if ((*header_bh)->b_blocknr == last_blk && extend) *extend = 0; @@ -3743,8 +3817,8 @@ static int ocfs2_extend_xattr_bucket(struct inode *inode, } /* Move half of the xattr in start_blk to the next bucket. */ - ret = ocfs2_half_xattr_bucket(inode, handle, start_blk, - start_blk + blk_per_bucket, NULL, 0); + ret = ocfs2_divide_xattr_bucket(inode, handle, start_blk, + start_blk + blk_per_bucket, NULL, 0); le16_add_cpu(&first_xh->xh_num_buckets, 1); ocfs2_journal_dirty(handle, first_bh); @@ -4435,11 +4509,21 @@ out: return ret; } -/* check whether the xattr bucket is filled up with the same hash value. */ +/* + * check whether the xattr bucket is filled up with the same hash value. + * If we want to insert the xattr with the same hash, return -ENOSPC. + * If we want to insert a xattr with different hash value, go ahead + * and ocfs2_divide_xattr_bucket will handle this. + */ static int ocfs2_check_xattr_bucket_collision(struct inode *inode, - struct ocfs2_xattr_bucket *bucket) + struct ocfs2_xattr_bucket *bucket, + const char *name) { struct ocfs2_xattr_header *xh = bucket->xh; + u32 name_hash = ocfs2_xattr_name_hash(inode, name, strlen(name)); + + if (name_hash != le32_to_cpu(xh->xh_entries[0].xe_name_hash)) + return 0; if (xh->xh_entries[le16_to_cpu(xh->xh_count) - 1].xe_name_hash == xh->xh_entries[0].xe_name_hash) { @@ -4562,7 +4646,9 @@ try_again: * one bucket's worth, so check it here whether we need to * add a new bucket for the insert. */ - ret = ocfs2_check_xattr_bucket_collision(inode, &xs->bucket); + ret = ocfs2_check_xattr_bucket_collision(inode, + &xs->bucket, + xi->name); if (ret) { mlog_errno(ret); goto out; |