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-rw-r--r--include/linux/blkdev_compat.h57
1 files changed, 48 insertions, 9 deletions
diff --git a/include/linux/blkdev_compat.h b/include/linux/blkdev_compat.h
index fbf30651f..8179aca6b 100644
--- a/include/linux/blkdev_compat.h
+++ b/include/linux/blkdev_compat.h
@@ -301,19 +301,58 @@ bio_set_flags_failfast(struct block_device *bdev, int *flags)
#endif /* HAVE_BDEV_LOGICAL_BLOCK_SIZE */
#endif /* HAVE_BDEV_PHYSICAL_BLOCK_SIZE */
+#ifndef HAVE_BIO_SET_OP_ATTRS
/*
- * 2.6.37 API change
- * The WRITE_FLUSH, WRITE_FUA, and WRITE_FLUSH_FUA flags have been
- * introduced as a replacement for WRITE_BARRIER. This was done to
- * allow richer semantics to be expressed to the block layer. It is
- * the block layers responsibility to choose the correct way to
- * implement these semantics.
+ * Kernels without bio_set_op_attrs use bi_rw for the bio flags.
*/
-#ifdef WRITE_FLUSH_FUA
-#define VDEV_WRITE_FLUSH_FUA WRITE_FLUSH_FUA
+static inline void
+bio_set_op_attrs(struct bio *bio, unsigned rw, unsigned flags)
+{
+ bio->bi_rw |= rw | flags;
+}
+#endif
+
+/*
+ * bio_set_flush - Set the appropriate flags in a bio to guarantee
+ * data are on non-volatile media on completion.
+ *
+ * 2.6.X - 2.6.36 API,
+ * WRITE_BARRIER - Tells the block layer to commit all previously submitted
+ * writes to stable storage before this one is started and that the current
+ * write is on stable storage upon completion. Also prevents reordering
+ * on both sides of the current operation.
+ *
+ * 2.6.37 - 4.8 API,
+ * Introduce WRITE_FLUSH, WRITE_FUA, and WRITE_FLUSH_FUA flags as a
+ * replacement for WRITE_BARRIER to allow expressing richer semantics
+ * to the block layer. It's up to the block layer to implement the
+ * semantics correctly. Use the WRITE_FLUSH_FUA flag combination.
+ *
+ * 4.8 - 4.9 API,
+ * REQ_FLUSH was renamed to REQ_PREFLUSH. For consistency with previous
+ * ZoL releases, prefer the WRITE_FLUSH_FUA flag set if it's available.
+ *
+ * 4.10 API,
+ * The read/write flags and their modifiers, including WRITE_FLUSH,
+ * WRITE_FUA and WRITE_FLUSH_FUA were removed from fs.h in
+ * torvalds/linux@70fd7614 and replaced by direct flag modification
+ * of the REQ_ flags in bio->bi_opf. Use REQ_PREFLUSH.
+ */
+static inline void
+bio_set_flush(struct bio *bio)
+{
+#if defined(WRITE_BARRIER) /* < 2.6.37 */
+ bio_set_op_attrs(bio, 0, WRITE_BARRIER);
+#elif defined(WRITE_FLUSH_FUA) /* >= 2.6.37 and <= 4.9 */
+ bio_set_op_attrs(bio, 0, WRITE_FLUSH_FUA);
+#elif defined(REQ_PREFLUSH) /* >= 4.10 */
+ bio_set_op_attrs(bio, 0, REQ_PREFLUSH);
#else
-#define VDEV_WRITE_FLUSH_FUA WRITE_BARRIER
+#error "Allowing the build will cause bio_set_flush requests to be ignored."
+ "Please file an issue report at: "
+ "https://github.com/zfsonlinux/zfs/issues/new"
#endif
+}
/*
* 4.8 - 4.x API,