--- /dev/null
+Index: linux-3.10.0-123.13.2.el7.x86_64/fs/ext4/mballoc.c
+===================================================================
+--- linux-3.10.0-123.13.2.el7.x86_64.orig/fs/ext4/mballoc.c
++++ linux-3.10.0-123.13.2.el7.x86_64/fs/ext4/mballoc.c
+@@ -3747,6 +3747,7 @@ ext4_mb_new_inode_pa(struct ext4_allocat
+ INIT_LIST_HEAD(&pa->pa_group_list);
+ pa->pa_deleted = 0;
+ pa->pa_type = MB_INODE_PA;
++ pa->pa_error = 0;
+
+ mb_debug(1, "new inode pa %p: %llu/%u for %u\n", pa,
+ pa->pa_pstart, pa->pa_len, pa->pa_lstart);
+@@ -3808,6 +3809,7 @@ ext4_mb_new_group_pa(struct ext4_allocat
+ INIT_LIST_HEAD(&pa->pa_group_list);
+ pa->pa_deleted = 0;
+ pa->pa_type = MB_GROUP_PA;
++ pa->pa_error = 0;
+
+ mb_debug(1, "new group pa %p: %llu/%u for %u\n", pa,
+ pa->pa_pstart, pa->pa_len, pa->pa_lstart);
+@@ -3868,7 +3870,9 @@ ext4_mb_release_inode_pa(struct ext4_bud
+ int err = 0;
+ int free = 0;
+
++ assert_spin_locked(ext4_group_lock_ptr(sb, e4b->bd_group));
+ BUG_ON(pa->pa_deleted == 0);
++ BUG_ON(pa->pa_inode == NULL);
+ ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit);
+ grp_blk_start = pa->pa_pstart - EXT4_C2B(sbi, bit);
+ BUG_ON(group != e4b->bd_group && pa->pa_len != 0);
+@@ -3891,12 +3895,18 @@ ext4_mb_release_inode_pa(struct ext4_bud
+ mb_free_blocks(pa->pa_inode, e4b, bit, next - bit);
+ bit = next + 1;
+ }
+- if (free != pa->pa_free) {
+- ext4_msg(e4b->bd_sb, KERN_CRIT,
+- "pa %p: logic %lu, phys. %lu, len %lu",
+- pa, (unsigned long) pa->pa_lstart,
+- (unsigned long) pa->pa_pstart,
+- (unsigned long) pa->pa_len);
++
++ /* "free < pa->pa_free" means we maybe double alloc the same blocks,
++ * otherwise maybe leave some free blocks unavailable, no need to BUG.*/
++ if ((free > pa->pa_free && !pa->pa_error) || (free < pa->pa_free)) {
++ ext4_error(sb, "pa free mismatch: [pa %p] "
++ "[phy %lu] [logic %lu] [len %u] [free %u] "
++ "[error %u] [inode %lu] [freed %u]", pa,
++ (unsigned long)pa->pa_pstart,
++ (unsigned long)pa->pa_lstart,
++ (unsigned)pa->pa_len, (unsigned)pa->pa_free,
++ (unsigned)pa->pa_error, pa->pa_inode->i_ino,
++ free);
+ ext4_grp_locked_error(sb, group, 0, 0, "free %u, pa_free %u",
+ free, pa->pa_free);
+ /*
+@@ -3904,6 +3914,8 @@ ext4_mb_release_inode_pa(struct ext4_bud
+ * from the bitmap and continue.
+ */
+ }
++ /* do not verify if the file system is being umounted */
++ BUG_ON(atomic_read(&sb->s_active) > 0 && pa->pa_free != free);
+ atomic_add(free, &sbi->s_mb_discarded);
+
+ return err;
+@@ -4661,6 +4673,25 @@ errout:
+ ac->ac_b_ex.fe_len = 0;
+ ar->len = 0;
+ ext4_mb_show_ac(ac);
++ if (ac->ac_pa) {
++ struct ext4_prealloc_space *pa = ac->ac_pa;
++
++ /* We can not make sure whether the bitmap has
++ * been updated or not when fail case. So can
++ * not revert pa_free back, just mark pa_error*/
++ pa->pa_error++;
++ ext4_error(sb,
++ "Updating bitmap error: [err %d] "
++ "[pa %p] [phy %lu] [logic %lu] "
++ "[len %u] [free %u] [error %u] "
++ "[inode %lu]", *errp, pa,
++ (unsigned long)pa->pa_pstart,
++ (unsigned long)pa->pa_lstart,
++ (unsigned)pa->pa_len,
++ (unsigned)pa->pa_free,
++ (unsigned)pa->pa_error,
++ pa->pa_inode ? pa->pa_inode->i_ino : 0);
++ }
+ }
+ ext4_mb_release_context(ac);
+ out:
+Index: linux-3.10.0-123.13.2.el7.x86_64/fs/ext4/mballoc.h
+===================================================================
+--- linux-3.10.0-123.13.2.el7.x86_64.orig/fs/ext4/mballoc.h
++++ linux-3.10.0-123.13.2.el7.x86_64/fs/ext4/mballoc.h
+@@ -19,6 +19,7 @@
+ #include <linux/seq_file.h>
+ #include <linux/blkdev.h>
+ #include <linux/mutex.h>
++#include <linux/genhd.h>
+ #include "ext4_jbd2.h"
+ #include "ext4.h"
+
+@@ -125,6 +126,7 @@ struct ext4_prealloc_space {
+ ext4_grpblk_t pa_len; /* len of preallocated chunk */
+ ext4_grpblk_t pa_free; /* how many blocks are free */
+ unsigned short pa_type; /* pa type. inode or group */
++ unsigned short pa_error;
+ spinlock_t *pa_obj_lock;
+ struct inode *pa_inode; /* hack, for history only */
+ };