LU-4993 llite: Support 3.14 kernel changes to bio api

In the 3.14 kernel code base several data fields in
struct bio were moved into a new structure called
bvec_iter. This changed impacted the lustre loop device.
This patch brings support of these changes to the loop
device lustre uses.

Change-Id: I7cc9565bbf56e87e4465a76b7b5b959b063c3971
Signed-off-by: James Simmons <uja.ornl@gmail.com>
Reviewed-on: http://review.whamcloud.com/10337
Tested-by: Jenkins
Reviewed-by: Bob Glossman <bob.glossman@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>

diff --git a/lustre/autoconf/lustre-core.m4 b/lustre/autoconf/lustre-core.m4
index 970593c..e14184d 100644 (file)
--- a/lustre/autoconf/lustre-core.m4
+++ b/lustre/autoconf/lustre-core.m4
@@ -1435,6 +1435,25 @@ vfs_unlink_3args, [
 ]) # LC_VFS_UNLINK_3ARGS
 
 #
+# LC_HAVE_BVEC_ITER
+#
+# 3.14 move some of its data in struct bio into the new
+# struct bvec_iter
+#
+AC_DEFUN([LC_HAVE_BVEC_ITER], [
+LB_CHECK_COMPILE([if Linux kernel has struct bvec_iter],
+have_bvec_iter, [
+       #include <linux/bio.h>
+],[
+       struct bvec_iter iter;
+       iter.bi_bvec_done = 0;
+], [
+       AC_DEFINE(HAVE_BVEC_ITER, 1,
+               [kernel has struct bvec_iter])
+])
+]) # LC_HAVE_BVEC_ITER
+
+#
 # LC_PROG_LINUX
 #
 # Lustre linux kernel checks
@@ -1551,6 +1570,9 @@ AC_DEFUN([LC_PROG_LINUX], [
        LC_VFS_RENAME_5ARGS
        LC_VFS_UNLINK_3ARGS
 
+       # 3.14
+       LC_HAVE_BVEC_ITER
+
        #
        AS_IF([test "x$enable_server" != xno], [
                LC_FUNC_DEV_SET_RDONLY

diff --git a/lustre/llite/lloop.c b/lustre/llite/lloop.c
index 55e3e6b..5c3bd7b 100644 (file)
--- a/lustre/llite/lloop.c
+++ b/lustre/llite/lloop.c
@@ -192,10 +192,15 @@ static int do_bio_lustrebacked(struct lloop_device *lo, struct bio *head)
         struct cl_object     *obj = ll_i2info(inode)->lli_clob;
         pgoff_t               offset;
         int                   ret;
-        int                   i;
+#ifdef HAVE_BVEC_ITER
+       struct bvec_iter      iter;
+       struct bio_vec        bvec;
+#else
+       int                   iter;
+       struct bio_vec       *bvec;
+#endif
         int                   rw;
         obd_count             page_count = 0;
-        struct bio_vec       *bvec;
         struct bio           *bio;
         ssize_t               bytes;
 
@@ -218,18 +223,30 @@ static int do_bio_lustrebacked(struct lloop_device *lo, struct bio *head)
         for (bio = head; bio != NULL; bio = bio->bi_next) {
                 LASSERT(rw == bio->bi_rw);
 
-                offset = (pgoff_t)(bio->bi_sector << 9) + lo->lo_offset;
-                bio_for_each_segment(bvec, bio, i) {
-                        BUG_ON(bvec->bv_offset != 0);
+#ifdef HAVE_BVEC_ITER
+               offset = (pgoff_t)(bio->bi_iter.bi_sector << 9) + lo->lo_offset;
+               bio_for_each_segment(bvec, bio, iter) {
+                       BUG_ON(bvec.bv_offset != 0);
+                       BUG_ON(bvec.bv_len != PAGE_CACHE_SIZE);
+
+                       pages[page_count] = bvec.bv_page;
+                       offsets[page_count] = offset;
+                       page_count++;
+                       offset += bvec.bv_len;
+#else
+               offset = (pgoff_t)(bio->bi_sector << 9) + lo->lo_offset;
+               bio_for_each_segment(bvec, bio, iter) {
+                       BUG_ON(bvec->bv_offset != 0);
                        BUG_ON(bvec->bv_len != PAGE_CACHE_SIZE);
 
-                        pages[page_count] = bvec->bv_page;
-                        offsets[page_count] = offset;
-                        page_count++;
-                        offset += bvec->bv_len;
-                }
-                LASSERT(page_count <= LLOOP_MAX_SEGMENTS);
-        }
+                       pages[page_count] = bvec->bv_page;
+                       offsets[page_count] = offset;
+                       page_count++;
+                       offset += bvec->bv_len;
+#endif
+               }
+               LASSERT(page_count <= LLOOP_MAX_SEGMENTS);
+       }
 
         ll_stats_ops_tally(ll_i2sbi(inode),
                         (rw == WRITE) ? LPROC_LL_BRW_WRITE : LPROC_LL_BRW_READ,
@@ -310,12 +327,17 @@ static unsigned int loop_get_bio(struct lloop_device *lo, struct bio **req)
         rw = first->bi_rw;
         bio = &lo->lo_bio;
         while (*bio && (*bio)->bi_rw == rw) {
-                CDEBUG(D_INFO, "bio sector %llu size %u count %u vcnt%u \n",
-                       (unsigned long long)(*bio)->bi_sector, (*bio)->bi_size,
-                       page_count, (*bio)->bi_vcnt);
-                if (page_count + (*bio)->bi_vcnt > LLOOP_MAX_SEGMENTS)
-                        break;
-
+#ifdef HAVE_BVEC_ITER
+               CDEBUG(D_INFO, "bio sector %llu size %u count %u vcnt%u \n",
+                      (unsigned long long)(*bio)->bi_iter.bi_sector,
+                      (*bio)->bi_iter.bi_size, page_count, (*bio)->bi_vcnt);
+#else
+               CDEBUG(D_INFO, "bio sector %llu size %u count %u vcnt%u \n",
+                      (unsigned long long)(*bio)->bi_sector, (*bio)->bi_size,
+                      page_count, (*bio)->bi_vcnt);
+#endif
+               if (page_count + (*bio)->bi_vcnt > LLOOP_MAX_SEGMENTS)
+                       break;
 
                 page_count += (*bio)->bi_vcnt;
                 count++;
@@ -345,8 +367,14 @@ loop_make_request(struct request_queue *q, struct bio *old_bio)
         if (!lo)
                 goto err;
 
-        CDEBUG(D_INFO, "submit bio sector %llu size %u\n",
-               (unsigned long long)old_bio->bi_sector, old_bio->bi_size);
+#ifdef HAVE_BVEC_ITER
+       CDEBUG(D_INFO, "submit bio sector %llu size %u\n",
+              (unsigned long long)old_bio->bi_iter.bi_sector,
+              old_bio->bi_iter.bi_size);
+#else
+       CDEBUG(D_INFO, "submit bio sector %llu size %u\n",
+              (unsigned long long)old_bio->bi_sector, old_bio->bi_size);
+#endif
 
        spin_lock_irq(&lo->lo_lock);
        inactive = (lo->lo_state != LLOOP_BOUND);