From f613dfcb3345dacb8cf99b7bb359acc1c18a1157 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Tue, 27 Jul 2010 11:56:08 -0400 Subject: [PATCH] ext4: check to make make sure bd_dev is set before dereferencing it There are some drivers which may not set bdev->bd_dev. So make sure it is non-NULL before dereferencing it. Google-Bug-Id: 1773557 Signed-off-by: "Theodore Ts'o" --- fs/ext4/super.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git a/fs/ext4/super.c b/fs/ext4/super.c index c1036bc8a539..e046eba24782 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -2304,6 +2304,8 @@ static ssize_t session_write_kbytes_show(struct ext4_attr *a, { struct super_block *sb = sbi->s_buddy_cache->i_sb; + if (!sb->s_bdev->bd_part) + return snprintf(buf, PAGE_SIZE, "0\n"); return snprintf(buf, PAGE_SIZE, "%lu\n", (part_stat_read(sb->s_bdev->bd_part, sectors[1]) - sbi->s_sectors_written_start) >> 1); @@ -2314,6 +2316,8 @@ static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a, { struct super_block *sb = sbi->s_buddy_cache->i_sb; + if (!sb->s_bdev->bd_part) + return snprintf(buf, PAGE_SIZE, "0\n"); return snprintf(buf, PAGE_SIZE, "%llu\n", (unsigned long long)(sbi->s_kbytes_written + ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) - @@ -2575,8 +2579,9 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) sbi->s_resgid = EXT4_DEF_RESGID; sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS; sbi->s_sb_block = sb_block; - sbi->s_sectors_written_start = part_stat_read(sb->s_bdev->bd_part, - sectors[1]); + if (sb->s_bdev->bd_part) + sbi->s_sectors_written_start = + part_stat_read(sb->s_bdev->bd_part, sectors[1]); unlock_kernel(); @@ -3492,10 +3497,14 @@ static int ext4_commit_super(struct super_block *sb, int sync) */ if (!(sb->s_flags & MS_RDONLY)) es->s_wtime = cpu_to_le32(get_seconds()); - es->s_kbytes_written = - cpu_to_le64(EXT4_SB(sb)->s_kbytes_written + + if (sb->s_bdev->bd_part) + es->s_kbytes_written = + cpu_to_le64(EXT4_SB(sb)->s_kbytes_written + ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) - EXT4_SB(sb)->s_sectors_written_start) >> 1)); + else + es->s_kbytes_written = + cpu_to_le64(EXT4_SB(sb)->s_kbytes_written); ext4_free_blocks_count_set(es, percpu_counter_sum_positive( &EXT4_SB(sb)->s_freeblocks_counter)); es->s_free_inodes_count = cpu_to_le32(percpu_counter_sum_positive( -- 2.39.5