2 files changed, 47 insertions, 17 deletions

diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
index da994374ec3b..30494c5da843 100644
--- a/fs/ext4/balloc.c
+++ b/fs/ext4/balloc.c
@@ -287,11 +287,11 @@ read_block_bitmap(struct super_block *sb, ext4_group_t block_group)
                             (int)block_group, (unsigned long long)bitmap_blk);
                 return NULL;
         }
-        if (!ext4_valid_block_bitmap(sb, desc, block_group, bh)) {
-                put_bh(bh);
-                return NULL;
-        }
-
+        ext4_valid_block_bitmap(sb, desc, block_group, bh);
+        /*
+         * file system mounted not to panic on error,
+         * continue with corrupt bitmap
+         */
         return bh;
 }
 /*
@@ -1770,7 +1770,12 @@ allocated:
                             "Allocating block in system zone - "
                             "blocks from %llu, length %lu",
                              ret_block, num);
-                goto out;
+                /*
+                 * claim_block marked the blocks we allocated
+                 * as in use. So we may want to selectively
+                 * mark some of the blocks as free
+                 */
+                goto retry_alloc;
         }
 
         performed_allocation = 1;
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 1d7fde994521..873ad9b3418c 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2736,7 +2736,7 @@ ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac,
         struct ext4_sb_info *sbi;
         struct super_block *sb;
         ext4_fsblk_t block;
-        int err;
+        int err, len;
 
         BUG_ON(ac->ac_status != AC_STATUS_FOUND);
         BUG_ON(ac->ac_b_ex.fe_len <= 0);
@@ -2770,14 +2770,27 @@ ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac,
                 + ac->ac_b_ex.fe_start
                 + le32_to_cpu(es->s_first_data_block);
 
-        if (block == ext4_block_bitmap(sb, gdp) ||
-                        block == ext4_inode_bitmap(sb, gdp) ||
-                        in_range(block, ext4_inode_table(sb, gdp),
-                                EXT4_SB(sb)->s_itb_per_group)) {
-
+        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)) {
                 ext4_error(sb, __func__,
                            "Allocating block in system zone - block = %llu",
                            block);
+                /* 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);
+                err = ext4_journal_dirty_metadata(handle, bitmap_bh);
+                if (!err)
+                        err = -EAGAIN;
+                goto out_err;
         }
 #ifdef AGGRESSIVE_CHECK
         {
@@ -4032,7 +4045,6 @@ ext4_fsblk_t ext4_mb_new_blocks(handle_t *handle,
 
                 ac->ac_op = EXT4_MB_HISTORY_ALLOC;
                 ext4_mb_normalize_request(ac, ar);
-
 repeat:
                 /* allocate space in core */
                 ext4_mb_regular_allocator(ac);
@@ -4046,10 +4058,21 @@ repeat:
         }
 
         if (likely(ac->ac_status == AC_STATUS_FOUND)) {
-                ext4_mb_mark_diskspace_used(ac, handle);
-                *errp = 0;
-                block = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
-                ar->len = ac->ac_b_ex.fe_len;
+                *errp = ext4_mb_mark_diskspace_used(ac, handle);
+                if (*errp ==  -EAGAIN) {
+                        ac->ac_b_ex.fe_group = 0;
+                        ac->ac_b_ex.fe_start = 0;
+                        ac->ac_b_ex.fe_len = 0;
+                        ac->ac_status = AC_STATUS_CONTINUE;
+                        goto repeat;
+                } else if (*errp) {
+                        ac->ac_b_ex.fe_len = 0;
+                        ar->len = 0;
+                        ext4_mb_show_ac(ac);
+                } else {
+                        block = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
+                        ar->len = ac->ac_b_ex.fe_len;
+                }
         } else {
                 freed  = ext4_mb_discard_preallocations(sb, ac->ac_o_ex.fe_len);
                 if (freed)
@@ -4236,6 +4259,8 @@ do_more:
                 ext4_error(sb, __func__,
                            "Freeing blocks in system zone - "
                            "Block = %lu, count = %lu", block, count);
+                /* err = 0. ext4_std_error should be a no op */
+                goto error_return;
         }
 
         BUFFER_TRACE(bitmap_bh, "getting write access");