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authorChristoph Hellwig <hch@infradead.org>2013-12-13 11:34:02 +1100
committerDave Chinner <david@fromorbit.com>2013-12-13 11:34:02 +1100
commitbde7cff67c39227c6ad503394e19e58debdbc5e3 (patch)
tree4325938342c4dece835e387e323106db53fe137d /fs/xfs/xfs_log.h
parent1234351cba958cd5d4338172ccfc869a687cd736 (diff)
downloadop-kernel-dev-bde7cff67c39227c6ad503394e19e58debdbc5e3.zip
op-kernel-dev-bde7cff67c39227c6ad503394e19e58debdbc5e3.tar.gz
xfs: format log items write directly into the linear CIL buffer
Instead of setting up pointers to memory locations in iop_format which then get copied into the CIL linear buffer after return move the copy into the individual inode items. This avoids the need to always have a memory block in the exact same layout that gets written into the log around, and allow the log items to be much more flexible in their in-memory layouts. The only caveat is that we need to properly align the data for each iovec so that don't have structures misaligned in subsequent iovecs. Note that all log item format routines now need to be careful to modify the copy of the item that was placed into the CIL after calls to xlog_copy_iovec instead of the in-memory copy. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
Diffstat (limited to 'fs/xfs/xfs_log.h')
-rw-r--r--fs/xfs/xfs_log.h41
1 files changed, 37 insertions, 4 deletions
diff --git a/fs/xfs/xfs_log.h b/fs/xfs/xfs_log.h
index 384c6c4..b0f4ef7 100644
--- a/fs/xfs/xfs_log.h
+++ b/fs/xfs/xfs_log.h
@@ -31,18 +31,51 @@ struct xfs_log_vec {
#define XFS_LOG_VEC_ORDERED (-1)
static inline void *
-xlog_copy_iovec(struct xfs_log_iovec **vecp, uint type, void *data, int len)
+xlog_prepare_iovec(struct xfs_log_vec *lv, struct xfs_log_iovec **vecp,
+ uint type)
{
struct xfs_log_iovec *vec = *vecp;
+ if (vec) {
+ ASSERT(vec - lv->lv_iovecp < lv->lv_niovecs);
+ vec++;
+ } else {
+ vec = &lv->lv_iovecp[0];
+ }
+
vec->i_type = type;
- vec->i_addr = data;
- vec->i_len = len;
+ vec->i_addr = lv->lv_buf + lv->lv_buf_len;
+
+ ASSERT(IS_ALIGNED((unsigned long)vec->i_addr, sizeof(uint64_t)));
- *vecp = vec + 1;
+ *vecp = vec;
return vec->i_addr;
}
+static inline void
+xlog_finish_iovec(struct xfs_log_vec *lv, struct xfs_log_iovec *vec, int len)
+{
+ /*
+ * We need to make sure the next buffer is naturally aligned for the
+ * biggest basic data type we put into it. We already accounted for
+ * this when sizing the buffer.
+ */
+ lv->lv_buf_len += round_up(len, sizeof(uint64_t));
+ vec->i_len = len;
+}
+
+static inline void *
+xlog_copy_iovec(struct xfs_log_vec *lv, struct xfs_log_iovec **vecp,
+ uint type, void *data, int len)
+{
+ void *buf;
+
+ buf = xlog_prepare_iovec(lv, vecp, type);
+ memcpy(buf, data, len);
+ xlog_finish_iovec(lv, *vecp, len);
+ return buf;
+}
+
/*
* Structure used to pass callback function and the function's argument
* to the log manager.
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