1 files changed, 67 insertions, 99 deletions

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index f871677a7984..ed8482e22c0e 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -372,24 +372,12 @@ static inline void mb_set_bit(int bit, void *addr)
         ext4_set_bit(bit, addr);
 }
 
-static inline void mb_set_bit_atomic(spinlock_t *lock, int bit, void *addr)
-{
-        addr = mb_correct_addr_and_bit(&bit, addr);
-        ext4_set_bit_atomic(lock, bit, addr);
-}
-
 static inline void mb_clear_bit(int bit, void *addr)
 {
         addr = mb_correct_addr_and_bit(&bit, addr);
         ext4_clear_bit(bit, addr);
 }
 
-static inline void mb_clear_bit_atomic(spinlock_t *lock, int bit, void *addr)
-{
-        addr = mb_correct_addr_and_bit(&bit, addr);
-        ext4_clear_bit_atomic(lock, bit, addr);
-}
-
 static inline int mb_find_next_zero_bit(void *addr, int max, int start)
 {
         int fix = 0, ret, tmpmax;
@@ -448,7 +436,7 @@ static void mb_free_blocks_double(struct inode *inode, struct ext4_buddy *e4b,
 
         if (unlikely(e4b->bd_info->bb_bitmap == NULL))
                 return;
-        BUG_ON(!ext4_is_group_locked(sb, e4b->bd_group));
+        assert_spin_locked(ext4_group_lock_ptr(sb, e4b->bd_group));
         for (i = 0; i < count; i++) {
                 if (!mb_test_bit(first + i, e4b->bd_info->bb_bitmap)) {
                         ext4_fsblk_t blocknr;
@@ -472,7 +460,7 @@ static void mb_mark_used_double(struct ext4_buddy *e4b, int first, int count)
 
         if (unlikely(e4b->bd_info->bb_bitmap == NULL))
                 return;
-        BUG_ON(!ext4_is_group_locked(e4b->bd_sb, e4b->bd_group));
+        assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group));
         for (i = 0; i < count; i++) {
                 BUG_ON(mb_test_bit(first + i, e4b->bd_info->bb_bitmap));
                 mb_set_bit(first + i, e4b->bd_info->bb_bitmap);
@@ -739,6 +727,7 @@ static void ext4_mb_generate_buddy(struct super_block *sb,
 
 static int ext4_mb_init_cache(struct page *page, char *incore)
 {
+        ext4_group_t ngroups;
         int blocksize;
         int blocks_per_page;
         int groups_per_page;
@@ -757,6 +746,7 @@ static int ext4_mb_init_cache(struct page *page, char *incore)
 
         inode = page->mapping->host;
         sb = inode->i_sb;
+        ngroups = ext4_get_groups_count(sb);
         blocksize = 1 << inode->i_blkbits;
         blocks_per_page = PAGE_CACHE_SIZE / blocksize;
 
@@ -780,7 +770,7 @@ static int ext4_mb_init_cache(struct page *page, char *incore)
         for (i = 0; i < groups_per_page; i++) {
                 struct ext4_group_desc *desc;
 
-                if (first_group + i >= EXT4_SB(sb)->s_groups_count)
+                if (first_group + i >= ngroups)
                         break;
 
                 err = -EIO;
@@ -801,17 +791,17 @@ static int ext4_mb_init_cache(struct page *page, char *incore)
                         unlock_buffer(bh[i]);
                         continue;
                 }
-                spin_lock(sb_bgl_lock(EXT4_SB(sb), first_group + i));
+                ext4_lock_group(sb, first_group + i);
                 if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
                         ext4_init_block_bitmap(sb, bh[i],
                                                 first_group + i, desc);
                         set_bitmap_uptodate(bh[i]);
                         set_buffer_uptodate(bh[i]);
-                        spin_unlock(sb_bgl_lock(EXT4_SB(sb), first_group + i));
+                        ext4_unlock_group(sb, first_group + i);
                         unlock_buffer(bh[i]);
                         continue;
                 }
-                spin_unlock(sb_bgl_lock(EXT4_SB(sb), first_group + i));
+                ext4_unlock_group(sb, first_group + i);
                 if (buffer_uptodate(bh[i])) {
                         /*
                          * if not uninit if bh is uptodate,
@@ -852,7 +842,7 @@ static int ext4_mb_init_cache(struct page *page, char *incore)
                 struct ext4_group_info *grinfo;
 
                 group = (first_block + i) >> 1;
-                if (group >= EXT4_SB(sb)->s_groups_count)
+                if (group >= ngroups)
                         break;
 
                 /*
@@ -1078,7 +1068,7 @@ static int mb_find_order_for_block(struct ext4_buddy *e4b, int block)
         return 0;
 }
 
-static void mb_clear_bits(spinlock_t *lock, void *bm, int cur, int len)
+static void mb_clear_bits(void *bm, int cur, int len)
 {
         __u32 *addr;
 
@@ -1091,15 +1081,12 @@ static void mb_clear_bits(spinlock_t *lock, void *bm, int cur, int len)
                         cur += 32;
                         continue;
                 }
-                if (lock)
-                        mb_clear_bit_atomic(lock, cur, bm);
-                else
-                        mb_clear_bit(cur, bm);
+                mb_clear_bit(cur, bm);
                 cur++;
         }
 }
 
-static void mb_set_bits(spinlock_t *lock, void *bm, int cur, int len)
+static void mb_set_bits(void *bm, int cur, int len)
 {
         __u32 *addr;
 
@@ -1112,10 +1099,7 @@ static void mb_set_bits(spinlock_t *lock, void *bm, int cur, int len)
                         cur += 32;
                         continue;
                 }
-                if (lock)
-                        mb_set_bit_atomic(lock, cur, bm);
-                else
-                        mb_set_bit(cur, bm);
+                mb_set_bit(cur, bm);
                 cur++;
         }
 }
@@ -1131,7 +1115,7 @@ static void mb_free_blocks(struct inode *inode, struct ext4_buddy *e4b,
         struct super_block *sb = e4b->bd_sb;
 
         BUG_ON(first + count > (sb->s_blocksize << 3));
-        BUG_ON(!ext4_is_group_locked(sb, e4b->bd_group));
+        assert_spin_locked(ext4_group_lock_ptr(sb, e4b->bd_group));
         mb_check_buddy(e4b);
         mb_free_blocks_double(inode, e4b, first, count);
 
@@ -1212,7 +1196,7 @@ static int mb_find_extent(struct ext4_buddy *e4b, int order, int block,
         int ord;
         void *buddy;
 
-        BUG_ON(!ext4_is_group_locked(e4b->bd_sb, e4b->bd_group));
+        assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group));
         BUG_ON(ex == NULL);
 
         buddy = mb_find_buddy(e4b, order, &max);
@@ -1276,7 +1260,7 @@ static int mb_mark_used(struct ext4_buddy *e4b, struct ext4_free_extent *ex)
 
         BUG_ON(start + len > (e4b->bd_sb->s_blocksize << 3));
         BUG_ON(e4b->bd_group != ex->fe_group);
-        BUG_ON(!ext4_is_group_locked(e4b->bd_sb, e4b->bd_group));
+        assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group));
         mb_check_buddy(e4b);
         mb_mark_used_double(e4b, start, len);
 
@@ -1330,8 +1314,7 @@ static int mb_mark_used(struct ext4_buddy *e4b, struct ext4_free_extent *ex)
                 e4b->bd_info->bb_counters[ord]++;
         }
 
-        mb_set_bits(sb_bgl_lock(EXT4_SB(e4b->bd_sb), ex->fe_group),
-                        EXT4_MB_BITMAP(e4b), ex->fe_start, len0);
+        mb_set_bits(EXT4_MB_BITMAP(e4b), ex->fe_start, len0);
         mb_check_buddy(e4b);
 
         return ret;
@@ -1726,7 +1709,6 @@ static int ext4_mb_good_group(struct ext4_allocation_context *ac,
         unsigned free, fragments;
         unsigned i, bits;
         int flex_size = ext4_flex_bg_size(EXT4_SB(ac->ac_sb));
-        struct ext4_group_desc *desc;
         struct ext4_group_info *grp = ext4_get_group_info(ac->ac_sb, group);
 
         BUG_ON(cr < 0 || cr >= 4);
@@ -1742,10 +1724,6 @@ static int ext4_mb_good_group(struct ext4_allocation_context *ac,
         switch (cr) {
         case 0:
                 BUG_ON(ac->ac_2order == 0);
-                /* If this group is uninitialized, skip it initially */
-                desc = ext4_get_group_desc(ac->ac_sb, group, NULL);
-                if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))
-                        return 0;
 
                 /* Avoid using the first bg of a flexgroup for data files */
                 if ((ac->ac_flags & EXT4_MB_HINT_DATA) &&
@@ -1788,6 +1766,7 @@ int ext4_mb_get_buddy_cache_lock(struct super_block *sb, ext4_group_t group)
         int block, pnum;
         int blocks_per_page;
         int groups_per_page;
+        ext4_group_t ngroups = ext4_get_groups_count(sb);
         ext4_group_t first_group;
         struct ext4_group_info *grp;
 
@@ -1807,7 +1786,7 @@ int ext4_mb_get_buddy_cache_lock(struct super_block *sb, ext4_group_t group)
         /* read all groups the page covers into the cache */
         for (i = 0; i < groups_per_page; i++) {
 
-                if ((first_group + i) >= EXT4_SB(sb)->s_groups_count)
+                if ((first_group + i) >= ngroups)
                         break;
                 grp = ext4_get_group_info(sb, first_group + i);
                 /* take all groups write allocation
@@ -1945,8 +1924,7 @@ err:
 static noinline_for_stack int
 ext4_mb_regular_allocator(struct ext4_allocation_context *ac)
 {
-        ext4_group_t group;
-        ext4_group_t i;
+        ext4_group_t ngroups, group, i;
         int cr;
         int err = 0;
         int bsbits;
@@ -1957,6 +1935,7 @@ ext4_mb_regular_allocator(struct ext4_allocation_context *ac)
 
         sb = ac->ac_sb;
         sbi = EXT4_SB(sb);
+        ngroups = ext4_get_groups_count(sb);
         BUG_ON(ac->ac_status == AC_STATUS_FOUND);
 
         /* first, try the goal */
@@ -2017,11 +1996,11 @@ repeat:
                  */
                 group = ac->ac_g_ex.fe_group;
 
-                for (i = 0; i < EXT4_SB(sb)->s_groups_count; group++, i++) {
+                for (i = 0; i < ngroups; group++, i++) {
                         struct ext4_group_info *grp;
                         struct ext4_group_desc *desc;
 
-                        if (group == EXT4_SB(sb)->s_groups_count)
+                        if (group == ngroups)
                                 group = 0;
 
                         /* quick check to skip empty groups */
@@ -2064,9 +2043,7 @@ repeat:
 
                         ac->ac_groups_scanned++;
                         desc = ext4_get_group_desc(sb, group, NULL);
-                        if (cr == 0 || (desc->bg_flags &
-                                        cpu_to_le16(EXT4_BG_BLOCK_UNINIT) &&
-                                        ac->ac_2order != 0))
+                        if (cr == 0)
                                 ext4_mb_simple_scan_group(ac, &e4b);
                         else if (cr == 1 &&
                                         ac->ac_g_ex.fe_len == sbi->s_stripe)
@@ -2315,12 +2292,10 @@ static struct file_operations ext4_mb_seq_history_fops = {
 static void *ext4_mb_seq_groups_start(struct seq_file *seq, loff_t *pos)
 {
         struct super_block *sb = seq->private;
-        struct ext4_sb_info *sbi = EXT4_SB(sb);
         ext4_group_t group;
 
-        if (*pos < 0 || *pos >= sbi->s_groups_count)
+        if (*pos < 0 || *pos >= ext4_get_groups_count(sb))
                 return NULL;
-
         group = *pos + 1;
         return (void *) ((unsigned long) group);
 }
@@ -2328,11 +2303,10 @@ static void *ext4_mb_seq_groups_start(struct seq_file *seq, loff_t *pos)
 static void *ext4_mb_seq_groups_next(struct seq_file *seq, void *v, loff_t *pos)
 {
         struct super_block *sb = seq->private;
-        struct ext4_sb_info *sbi = EXT4_SB(sb);
         ext4_group_t group;
 
         ++*pos;
-        if (*pos < 0 || *pos >= sbi->s_groups_count)
+        if (*pos < 0 || *pos >= ext4_get_groups_count(sb))
                 return NULL;
         group = *pos + 1;
         return (void *) ((unsigned long) group);
@@ -2420,7 +2394,8 @@ static void ext4_mb_history_release(struct super_block *sb)
 
         if (sbi->s_proc != NULL) {
                 remove_proc_entry("mb_groups", sbi->s_proc);
-                remove_proc_entry("mb_history", sbi->s_proc);
+                if (sbi->s_mb_history_max)
+                        remove_proc_entry("mb_history", sbi->s_proc);
         }
         kfree(sbi->s_mb_history);
 }
@@ -2431,17 +2406,17 @@ static void ext4_mb_history_init(struct super_block *sb)
         int i;
 
         if (sbi->s_proc != NULL) {
-                proc_create_data("mb_history", S_IRUGO, sbi->s_proc,
-                                 &ext4_mb_seq_history_fops, sb);
+                if (sbi->s_mb_history_max)
+                        proc_create_data("mb_history", S_IRUGO, sbi->s_proc,
+                                         &ext4_mb_seq_history_fops, sb);
                 proc_create_data("mb_groups", S_IRUGO, sbi->s_proc,
                                  &ext4_mb_seq_groups_fops, sb);
         }
 
-        sbi->s_mb_history_max = 1000;
         sbi->s_mb_history_cur = 0;
         spin_lock_init(&sbi->s_mb_history_lock);
         i = sbi->s_mb_history_max * sizeof(struct ext4_mb_history);
-        sbi->s_mb_history = kzalloc(i, GFP_KERNEL);
+        sbi->s_mb_history = i ? kzalloc(i, GFP_KERNEL) : NULL;
         /* if we can't allocate history, then we simple won't use it */
 }
 
@@ -2451,7 +2426,7 @@ ext4_mb_store_history(struct ext4_allocation_context *ac)
         struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
         struct ext4_mb_history h;
 
-        if (unlikely(sbi->s_mb_history == NULL))
+        if (sbi->s_mb_history == NULL)
                 return;
 
         if (!(ac->ac_op & sbi->s_mb_history_filter))
@@ -2587,6 +2562,7 @@ void ext4_mb_update_group_info(struct ext4_group_info *grp, ext4_grpblk_t add)
 
 static int ext4_mb_init_backend(struct super_block *sb)
 {
+        ext4_group_t ngroups = ext4_get_groups_count(sb);
         ext4_group_t i;
         int metalen;
         struct ext4_sb_info *sbi = EXT4_SB(sb);
@@ -2598,7 +2574,7 @@ static int ext4_mb_init_backend(struct super_block *sb)
         struct ext4_group_desc *desc;
 
         /* This is the number of blocks used by GDT */
-        num_meta_group_infos = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) -
+        num_meta_group_infos = (ngroups + EXT4_DESC_PER_BLOCK(sb) -
                                 1) >> EXT4_DESC_PER_BLOCK_BITS(sb);
 
         /*
@@ -2644,7 +2620,7 @@ static int ext4_mb_init_backend(struct super_block *sb)
         for (i = 0; i < num_meta_group_infos; i++) {
                 if ((i + 1) == num_meta_group_infos)
                         metalen = sizeof(*meta_group_info) *
-                                (sbi->s_groups_count -
+                                (ngroups -
                                         (i << EXT4_DESC_PER_BLOCK_BITS(sb)));
                 meta_group_info = kmalloc(metalen, GFP_KERNEL);
                 if (meta_group_info == NULL) {
@@ -2655,7 +2631,7 @@ static int ext4_mb_init_backend(struct super_block *sb)
                 sbi->s_group_info[i] = meta_group_info;
         }
 
-        for (i = 0; i < sbi->s_groups_count; i++) {
+        for (i = 0; i < ngroups; i++) {
                 desc = ext4_get_group_desc(sb, i, NULL);
                 if (desc == NULL) {
                         printk(KERN_ERR
@@ -2761,7 +2737,7 @@ int ext4_mb_init(struct super_block *sb, int needs_recovery)
         return 0;
 }
 
-/* need to called with ext4 group lock (ext4_lock_group) */
+/* need to called with the ext4 group lock held */
 static void ext4_mb_cleanup_pa(struct ext4_group_info *grp)
 {
         struct ext4_prealloc_space *pa;
@@ -2781,13 +2757,14 @@ static void ext4_mb_cleanup_pa(struct ext4_group_info *grp)
 
 int ext4_mb_release(struct super_block *sb)
 {
+        ext4_group_t ngroups = ext4_get_groups_count(sb);
         ext4_group_t i;
         int num_meta_group_infos;
         struct ext4_group_info *grinfo;
         struct ext4_sb_info *sbi = EXT4_SB(sb);
 
         if (sbi->s_group_info) {
-                for (i = 0; i < sbi->s_groups_count; i++) {
+                for (i = 0; i < ngroups; i++) {
                         grinfo = ext4_get_group_info(sb, i);
 #ifdef DOUBLE_CHECK
                         kfree(grinfo->bb_bitmap);
@@ -2797,7 +2774,7 @@ int ext4_mb_release(struct super_block *sb)
                         ext4_unlock_group(sb, i);
                         kfree(grinfo);
                 }
-                num_meta_group_infos = (sbi->s_groups_count +
+                num_meta_group_infos = (ngroups +
                                 EXT4_DESC_PER_BLOCK(sb) - 1) >>
                         EXT4_DESC_PER_BLOCK_BITS(sb);
                 for (i = 0; i < num_meta_group_infos; i++)
@@ -2984,27 +2961,25 @@ ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac,
                 + le32_to_cpu(es->s_first_data_block);
 
         len = ac->ac_b_ex.fe_len;
-        if (in_range(ext4_block_bitmap(sb, gdp), block, len) ||
-            in_range(ext4_inode_bitmap(sb, gdp), block, len) ||
-            in_range(block, ext4_inode_table(sb, gdp),
-                     EXT4_SB(sb)->s_itb_per_group) ||
-            in_range(block + len - 1, ext4_inode_table(sb, gdp),
-                     EXT4_SB(sb)->s_itb_per_group)) {
+        if (!ext4_data_block_valid(sbi, block, len)) {
                 ext4_error(sb, __func__,
-                           "Allocating block %llu in system zone of %d group\n",
-                           block, ac->ac_b_ex.fe_group);
+                           "Allocating blocks %llu-%llu which overlap "
+                           "fs metadata\n", block, block+len);
                 /* File system mounted not to panic on error
                  * Fix the bitmap and repeat the block allocation
                  * We leak some of the blocks here.
                  */
-                mb_set_bits(sb_bgl_lock(sbi, ac->ac_b_ex.fe_group),
-                                bitmap_bh->b_data, ac->ac_b_ex.fe_start,
-                                ac->ac_b_ex.fe_len);
+                ext4_lock_group(sb, ac->ac_b_ex.fe_group);
+                mb_set_bits(bitmap_bh->b_data, ac->ac_b_ex.fe_start,
+                            ac->ac_b_ex.fe_len);
+                ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
                 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
                 if (!err)
                         err = -EAGAIN;
                 goto out_err;
         }
+
+        ext4_lock_group(sb, ac->ac_b_ex.fe_group);
 #ifdef AGGRESSIVE_CHECK
         {
                 int i;
@@ -3014,9 +2989,7 @@ ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac,
                 }
         }
 #endif
-        spin_lock(sb_bgl_lock(sbi, ac->ac_b_ex.fe_group));
-        mb_set_bits(NULL, bitmap_bh->b_data,
-                                ac->ac_b_ex.fe_start, ac->ac_b_ex.fe_len);
+        mb_set_bits(bitmap_bh->b_data, ac->ac_b_ex.fe_start,ac->ac_b_ex.fe_len);
         if (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
                 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
                 ext4_free_blks_set(sb, gdp,
@@ -3026,7 +2999,8 @@ ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac,
         len = ext4_free_blks_count(sb, gdp) - ac->ac_b_ex.fe_len;
         ext4_free_blks_set(sb, gdp, len);
         gdp->bg_checksum = ext4_group_desc_csum(sbi, ac->ac_b_ex.fe_group, gdp);
-        spin_unlock(sb_bgl_lock(sbi, ac->ac_b_ex.fe_group));
+
+        ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
         percpu_counter_sub(&sbi->s_freeblocks_counter, ac->ac_b_ex.fe_len);
         /*
          * Now reduce the dirty block count also. Should not go negative
@@ -3459,7 +3433,7 @@ ext4_mb_use_preallocated(struct ext4_allocation_context *ac)
  * the function goes through all block freed in the group
  * but not yet committed and marks them used in in-core bitmap.
  * buddy must be generated from this bitmap
- * Need to be called with ext4 group lock (ext4_lock_group)
+ * Need to be called with the ext4 group lock held
  */
 static void ext4_mb_generate_from_freelist(struct super_block *sb, void *bitmap,
                                                 ext4_group_t group)
@@ -3473,9 +3447,7 @@ static void ext4_mb_generate_from_freelist(struct super_block *sb, void *bitmap,
 
         while (n) {
                 entry = rb_entry(n, struct ext4_free_data, node);
-                mb_set_bits(sb_bgl_lock(EXT4_SB(sb), group),
-                                bitmap, entry->start_blk,
-                                entry->count);
+                mb_set_bits(bitmap, entry->start_blk, entry->count);
                 n = rb_next(n);
         }
         return;
@@ -3484,7 +3456,7 @@ static void ext4_mb_generate_from_freelist(struct super_block *sb, void *bitmap,
 /*
  * the function goes through all preallocation in this group and marks them
  * used in in-core bitmap. buddy must be generated from this bitmap
- * Need to be called with ext4 group lock (ext4_lock_group)
+ * Need to be called with ext4 group lock held
  */
 static void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
                                         ext4_group_t group)
@@ -3516,8 +3488,7 @@ static void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
                 if (unlikely(len == 0))
                         continue;
                 BUG_ON(groupnr != group);
-                mb_set_bits(sb_bgl_lock(EXT4_SB(sb), group),
-                                                bitmap, start, len);
+                mb_set_bits(bitmap, start, len);
                 preallocated += len;
                 count++;
         }
@@ -4121,7 +4092,7 @@ static void ext4_mb_return_to_preallocation(struct inode *inode,
 static void ext4_mb_show_ac(struct ext4_allocation_context *ac)
 {
         struct super_block *sb = ac->ac_sb;
-        ext4_group_t i;
+        ext4_group_t ngroups, i;
 
         printk(KERN_ERR "EXT4-fs: Can't allocate:"
                         " Allocation context details:\n");
@@ -4145,7 +4116,8 @@ static void ext4_mb_show_ac(struct ext4_allocation_context *ac)
         printk(KERN_ERR "EXT4-fs: %lu scanned, %d found\n", ac->ac_ex_scanned,
                 ac->ac_found);
         printk(KERN_ERR "EXT4-fs: groups: \n");
-        for (i = 0; i < EXT4_SB(sb)->s_groups_count; i++) {
+        ngroups = ext4_get_groups_count(sb);
+        for (i = 0; i < ngroups; i++) {
                 struct ext4_group_info *grp = ext4_get_group_info(sb, i);
                 struct ext4_prealloc_space *pa;
                 ext4_grpblk_t start;
@@ -4469,13 +4441,13 @@ static int ext4_mb_release_context(struct ext4_allocation_context *ac)
 
 static int ext4_mb_discard_preallocations(struct super_block *sb, int needed)
 {
-        ext4_group_t i;
+        ext4_group_t i, ngroups = ext4_get_groups_count(sb);
         int ret;
         int freed = 0;
 
         trace_mark(ext4_mb_discard_preallocations, "dev %s needed %d",
                    sb->s_id, needed);
-        for (i = 0; i < EXT4_SB(sb)->s_groups_count && needed > 0; i++) {
+        for (i = 0; i < ngroups && needed > 0; i++) {
                 ret = ext4_mb_discard_group_preallocations(sb, i, needed);
                 freed += ret;
                 needed -= ret;
@@ -4859,29 +4831,25 @@ do_more:
                 new_entry->group  = block_group;
                 new_entry->count = count;
                 new_entry->t_tid = handle->h_transaction->t_tid;
+
                 ext4_lock_group(sb, block_group);
-                mb_clear_bits(sb_bgl_lock(sbi, block_group), bitmap_bh->b_data,
-                                bit, count);
+                mb_clear_bits(bitmap_bh->b_data, bit, count);
                 ext4_mb_free_metadata(handle, &e4b, new_entry);
-                ext4_unlock_group(sb, block_group);
         } else {
-                ext4_lock_group(sb, block_group);
                 /* need to update group_info->bb_free and bitmap
                  * with group lock held. generate_buddy look at
                  * them with group lock_held
                  */
-                mb_clear_bits(sb_bgl_lock(sbi, block_group), bitmap_bh->b_data,
-                                bit, count);
+                ext4_lock_group(sb, block_group);
+                mb_clear_bits(bitmap_bh->b_data, bit, count);
                 mb_free_blocks(inode, &e4b, bit, count);
                 ext4_mb_return_to_preallocation(inode, &e4b, block, count);
-                ext4_unlock_group(sb, block_group);
         }
 
-        spin_lock(sb_bgl_lock(sbi, block_group));
         ret = ext4_free_blks_count(sb, gdp) + count;
         ext4_free_blks_set(sb, gdp, ret);
         gdp->bg_checksum = ext4_group_desc_csum(sbi, block_group, gdp);
-        spin_unlock(sb_bgl_lock(sbi, block_group));
+        ext4_unlock_group(sb, block_group);
         percpu_counter_add(&sbi->s_freeblocks_counter, count);
 
         if (sbi->s_log_groups_per_flex) {