1 files changed, 81 insertions, 20 deletions

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 74e495dabe09..c1e19d5b5985 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2529,7 +2529,6 @@ static void release_blocks_on_commit(journal_t *journal, transaction_t *txn)
         struct ext4_group_info *db;
         int err, count = 0, count2 = 0;
         struct ext4_free_data *entry;
-        ext4_fsblk_t discard_block;
         struct list_head *l, *ltmp;
 
         list_for_each_safe(l, ltmp, &txn->t_private_list) {
@@ -2559,13 +2558,19 @@ static void release_blocks_on_commit(journal_t *journal, transaction_t *txn)
                         page_cache_release(e4b.bd_bitmap_page);
                 }
                 ext4_unlock_group(sb, entry->group);
-                discard_block = (ext4_fsblk_t) entry->group * EXT4_BLOCKS_PER_GROUP(sb)
-                        + entry->start_blk
-                        + le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
-                trace_ext4_discard_blocks(sb, (unsigned long long)discard_block,
-                                          entry->count);
-                sb_issue_discard(sb, discard_block, entry->count);
-
+                if (test_opt(sb, DISCARD)) {
+                        ext4_fsblk_t discard_block;
+                        struct ext4_super_block *es = EXT4_SB(sb)->s_es;
+
+                        discard_block = (ext4_fsblk_t)entry->group *
+                                                EXT4_BLOCKS_PER_GROUP(sb)
+                                        + entry->start_blk
+                                        + le32_to_cpu(es->s_first_data_block);
+                        trace_ext4_discard_blocks(sb,
+                                        (unsigned long long)discard_block,
+                                        entry->count);
+                        sb_issue_discard(sb, discard_block, entry->count);
+                }
                 kmem_cache_free(ext4_free_ext_cachep, entry);
                 ext4_mb_release_desc(&e4b);
         }
@@ -3006,6 +3011,24 @@ static void ext4_mb_collect_stats(struct ext4_allocation_context *ac)
 }
 
 /*
+ * Called on failure; free up any blocks from the inode PA for this
+ * context.  We don't need this for MB_GROUP_PA because we only change
+ * pa_free in ext4_mb_release_context(), but on failure, we've already
+ * zeroed out ac->ac_b_ex.fe_len, so group_pa->pa_free is not changed.
+ */
+static void ext4_discard_allocated_blocks(struct ext4_allocation_context *ac)
+{
+        struct ext4_prealloc_space *pa = ac->ac_pa;
+        int len;
+
+        if (pa && pa->pa_type == MB_INODE_PA) {
+                len = ac->ac_b_ex.fe_len;
+                pa->pa_free += len;
+        }
+
+}
+
+/*
  * use blocks preallocated to inode
  */
 static void ext4_mb_use_inode_pa(struct ext4_allocation_context *ac,
@@ -4290,6 +4313,7 @@ repeat:
                         ac->ac_status = AC_STATUS_CONTINUE;
                         goto repeat;
                 } else if (*errp) {
+                        ext4_discard_allocated_blocks(ac);
                         ac->ac_b_ex.fe_len = 0;
                         ar->len = 0;
                         ext4_mb_show_ac(ac);
@@ -4422,18 +4446,24 @@ ext4_mb_free_metadata(handle_t *handle, struct ext4_buddy *e4b,
         return 0;
 }
 
-/*
- * Main entry point into mballoc to free blocks
+/**
+ * ext4_free_blocks() -- Free given blocks and update quota
+ * @handle:             handle for this transaction
+ * @inode:              inode
+ * @block:              start physical block to free
+ * @count:              number of blocks to count
+ * @metadata:           Are these metadata blocks
  */
-void ext4_mb_free_blocks(handle_t *handle, struct inode *inode,
-                        ext4_fsblk_t block, unsigned long count,
-                        int metadata, unsigned long *freed)
+void ext4_free_blocks(handle_t *handle, struct inode *inode,
+                      struct buffer_head *bh, ext4_fsblk_t block,
+                      unsigned long count, int flags)
 {
         struct buffer_head *bitmap_bh = NULL;
         struct super_block *sb = inode->i_sb;
         struct ext4_allocation_context *ac = NULL;
         struct ext4_group_desc *gdp;
         struct ext4_super_block *es;
+        unsigned long freed = 0;
         unsigned int overflow;
         ext4_grpblk_t bit;
         struct buffer_head *gd_bh;
@@ -4443,13 +4473,16 @@ void ext4_mb_free_blocks(handle_t *handle, struct inode *inode,
         int err = 0;
         int ret;
 
-        *freed = 0;
+        if (bh) {
+                if (block)
+                        BUG_ON(block != bh->b_blocknr);
+                else
+                        block = bh->b_blocknr;
+        }
 
         sbi = EXT4_SB(sb);
         es = EXT4_SB(sb)->s_es;
-        if (block < le32_to_cpu(es->s_first_data_block) ||
-            block + count < block ||
-            block + count > ext4_blocks_count(es)) {
+        if (!ext4_data_block_valid(sbi, block, count)) {
                 ext4_error(sb, __func__,
                             "Freeing blocks not in datazone - "
                             "block = %llu, count = %lu", block, count);
@@ -4457,7 +4490,32 @@ void ext4_mb_free_blocks(handle_t *handle, struct inode *inode,
         }
 
         ext4_debug("freeing block %llu\n", block);
-        trace_ext4_free_blocks(inode, block, count, metadata);
+        trace_ext4_free_blocks(inode, block, count, flags);
+
+        if (flags & EXT4_FREE_BLOCKS_FORGET) {
+                struct buffer_head *tbh = bh;
+                int i;
+
+                BUG_ON(bh && (count > 1));
+
+                for (i = 0; i < count; i++) {
+                        if (!bh)
+                                tbh = sb_find_get_block(inode->i_sb,
+                                                        block + i);
+                        ext4_forget(handle, flags & EXT4_FREE_BLOCKS_METADATA, 
+                                    inode, tbh, block + i);
+                }
+        }
+
+        /* 
+         * We need to make sure we don't reuse the freed block until
+         * after the transaction is committed, which we can do by
+         * treating the block as metadata, below.  We make an
+         * exception if the inode is to be written in writeback mode
+         * since writeback mode has weak data consistency guarantees.
+         */
+        if (!ext4_should_writeback_data(inode))
+                flags |= EXT4_FREE_BLOCKS_METADATA;
 
         ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS);
         if (ac) {
@@ -4533,7 +4591,8 @@ do_more:
         err = ext4_mb_load_buddy(sb, block_group, &e4b);
         if (err)
                 goto error_return;
-        if (metadata && ext4_handle_valid(handle)) {
+
+        if ((flags & EXT4_FREE_BLOCKS_METADATA) && ext4_handle_valid(handle)) {
                 struct ext4_free_data *new_entry;
                 /*
                  * blocks being freed are metadata. these blocks shouldn't
@@ -4572,7 +4631,7 @@ do_more:
 
         ext4_mb_release_desc(&e4b);
 
-        *freed += count;
+        freed += count;
 
         /* We dirtied the bitmap block */
         BUFFER_TRACE(bitmap_bh, "dirtied bitmap block");
@@ -4592,6 +4651,8 @@ do_more:
         }
         sb->s_dirt = 1;
 error_return:
+        if (freed)
+                vfs_dq_free_block(inode, freed);
         brelse(bitmap_bh);
         ext4_std_error(sb, err);
         if (ac)