From 27f2044484dbc177d9ad5a3d9dcf5a23a3ed2a18 Mon Sep 17 00:00:00 2001
From: shadow <shadow>
Date: Tue, 8 Sep 2009 08:09:28 +0000
Subject: [PATCH] resolve race with saving updates to lov_objid file.

Branch HEAD
b=20464
i=adilger
i=green
---
 libcfs/include/libcfs/bitmap.h      | 12 +++++++++---
 libcfs/include/libcfs/user-bitops.h |  8 ++++++--
 lustre/include/liblustre.h          | 30 ------------------------------
 lustre/mdd/mdd_lov.c                |  2 ++
 lustre/mds/mds_lov.c                |  8 ++++++--
 5 files changed, 23 insertions(+), 37 deletions(-)

diff --git a/libcfs/include/libcfs/bitmap.h b/libcfs/include/libcfs/bitmap.h
index 1d795de..a593701 100644
--- a/libcfs/include/libcfs/bitmap.h
+++ b/libcfs/include/libcfs/bitmap.h
@@ -64,19 +64,25 @@ bitmap_t *ALLOCATE_BITMAP(int size)
 static inline
 void cfs_bitmap_set(bitmap_t *bitmap, int nbit)
 {
-	set_bit(nbit, bitmap->data);
+        set_bit(nbit, bitmap->data);
 }
 
 static inline
 void cfs_bitmap_clear(bitmap_t *bitmap, int nbit)
 {
-        clear_bit(nbit, bitmap->data);
+        test_and_clear_bit(nbit, bitmap->data);
 }
 
 static inline
 int cfs_bitmap_check(bitmap_t *bitmap, int nbit)
 {
-	return test_bit(nbit, bitmap->data);
+        return test_bit(nbit, bitmap->data);
+}
+
+static inline
+int cfs_bitmap_test_and_clear(bitmap_t *bitmap, int nbit)
+{
+        return test_and_clear_bit(nbit, bitmap->data);
 }
 
 /* return 0 is bitmap has none set bits */
diff --git a/libcfs/include/libcfs/user-bitops.h b/libcfs/include/libcfs/user-bitops.h
index ae7d569..cd0d220 100644
--- a/libcfs/include/libcfs/user-bitops.h
+++ b/libcfs/include/libcfs/user-bitops.h
@@ -42,7 +42,7 @@
 #define __LIBCFS_USER_BITOPS_H__
 
 /* test if bit nr is set in bitmap addr; returns previous value of bit nr */
-static __inline__ int set_bit(int nr, unsigned long *addr)
+static __inline__ int test_and_set_bit(int nr, unsigned long *addr)
 {
         unsigned long mask;
 
@@ -53,8 +53,10 @@ static __inline__ int set_bit(int nr, unsigned long *addr)
         return nr;
 }
 
+#define set_bit(n, a) test_and_set_bit(n, a)
+
 /* clear bit nr in bitmap addr; returns previous value of bit nr*/
-static __inline__ int clear_bit(int nr, unsigned long *addr)
+static __inline__ int test_and_clear_bit(int nr, unsigned long *addr)
 {
         unsigned long mask;
 
@@ -65,6 +67,8 @@ static __inline__ int clear_bit(int nr, unsigned long *addr)
         return nr;
 }
 
+#define clear_bit(n, a) test_and_clear_bit(n, a)
+
 static __inline__ int test_bit(int nr, const unsigned long *addr)
 {
         return ((1UL << (nr & (BITS_PER_LONG - 1))) &
diff --git a/lustre/include/liblustre.h b/lustre/include/liblustre.h
index de9f343..8a3332d 100644
--- a/lustre/include/liblustre.h
+++ b/lustre/include/liblustre.h
@@ -324,36 +324,6 @@ int in_group_p(gid_t gid);
 #define might_sleep_if(c)
 #define smp_mb()
 
-static inline
-int test_and_set_bit(int nr, unsigned long *addr)
-{
-        int oldbit;
-
-        while (nr >= sizeof(long)) {
-                nr -= sizeof(long);
-                addr++;
-        }
-
-        oldbit = (*addr) & (1 << nr);
-        *addr |= (1 << nr);
-        return oldbit;
-}
-
-static inline
-int test_and_clear_bit(int nr, unsigned long *addr)
-{
-        int oldbit;
-
-        while (nr >= sizeof(long)) {
-                nr -= sizeof(long);
-                addr++;
-        }
-
-        oldbit = (*addr) & (1 << nr);
-        *addr &= ~(1 << nr);
-        return oldbit;
-}
-
 #define libcfs_memory_pressure_get() (0) 
 #define libcfs_memory_pressure_put() do {} while (0) 
 #define libcfs_memory_pressure_clr() do {} while (0)
diff --git a/lustre/mdd/mdd_lov.c b/lustre/mdd/mdd_lov.c
index bbf079a..d692736 100644
--- a/lustre/mdd/mdd_lov.c
+++ b/lustre/mdd/mdd_lov.c
@@ -410,6 +410,8 @@ int mdd_lov_create(const struct lu_env *env, struct mdd_device *mdd,
         if (spec->no_create != 0) {
                 *lmm = (struct lov_mds_md *)spec->u.sp_ea.eadata;
                 *lmm_size = spec->u.sp_ea.eadatalen;
+                LASSERT(*lmm_size == lov_mds_md_size((*lmm)->lmm_stripe_count,
+                                                     (*lmm)->lmm_magic));
                 RETURN(0);
         }
 
diff --git a/lustre/mds/mds_lov.c b/lustre/mds/mds_lov.c
index 39f2092..80b1658 100644
--- a/lustre/mds/mds_lov.c
+++ b/lustre/mds/mds_lov.c
@@ -452,6 +452,9 @@ int mds_lov_write_objids(struct obd_device *obd)
 
                 LASSERT(data != NULL);
 
+                if (!cfs_bitmap_test_and_clear(mds->mds_lov_page_dirty, i))
+                        continue;
+
                 /* check for particaly filled last page */
                 if (i == mds->mds_lov_objid_lastpage)
                         size = (mds->mds_lov_objid_lastidx+1) * sizeof(obd_id);
@@ -459,9 +462,10 @@ int mds_lov_write_objids(struct obd_device *obd)
                 CDEBUG(D_INFO, "write %lld - %u\n", off, size);
                 rc = fsfilt_write_record(obd, mds->mds_lov_objid_filp, data,
                                          size, &off, 0);
-                if (rc < 0)
+                if (rc < 0) {
+                        cfs_bitmap_set(mds->mds_lov_page_dirty, i);
                         break;
-                cfs_bitmap_clear(mds->mds_lov_page_dirty, i);
+                }
         }
         if (rc >= 0)
                 rc = 0;
-- 
1.8.3.1