ext4: fix trimming starting with block 0 with small blocksize

[pandora-kernel.git] / fs / ext4 / mballoc.c

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index cd5214f..851f49b 100644 (file)
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -4804,11 +4804,12 @@ ext4_grpblk_t ext4_trim_all_free(struct super_block *sb, struct ext4_buddy *e4b,
 int ext4_trim_fs(struct super_block *sb, struct fstrim_range *range)
 {
        struct ext4_buddy e4b;
-       ext4_fsblk_t blocks_count = ext4_blocks_count(EXT4_SB(sb)->s_es);
        ext4_group_t first_group, last_group;
        ext4_group_t group, ngroups = ext4_get_groups_count(sb);
        ext4_grpblk_t cnt = 0, first_block, last_block;
        uint64_t start, len, minlen, trimmed;
+       ext4_fsblk_t first_data_blk =
+                       le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
        int ret = 0;
 
        start = range->start >> sb->s_blocksize_bits;
@@ -4816,13 +4817,12 @@ int ext4_trim_fs(struct super_block *sb, struct fstrim_range *range)
        minlen = range->minlen >> sb->s_blocksize_bits;
        trimmed = 0;
 
-       if (start >= blocks_count)
-               return -EINVAL;
-       if (start + len > blocks_count)
-               len = blocks_count - start;
-
        if (unlikely(minlen > EXT4_BLOCKS_PER_GROUP(sb)))
                return -EINVAL;
+       if (start < first_data_blk) {
+               len -= first_data_blk - start;
+               start = first_data_blk;
+       }
 
        /* Determine first and last group to examine based on start and len */
        ext4_get_group_no_and_offset(sb, (ext4_fsblk_t) start,