From e43bb4e612b402a631bc549ac496f78bc7a79438 Mon Sep 17 00:00:00 2001 From: Namjae Jeon Date: Thu, 26 Jun 2014 10:11:53 -0400 Subject: ext4: decrement free clusters/inodes counters when block group declared bad We should decrement free clusters counter when block bitmap is marked as corrupt and free inodes counter when the allocation bitmap is marked as corrupt to avoid misunderstanding due to incorrect available size in statfs result. User can get immediately ENOSPC error from write begin without reaching for the writepages. Cc: Darrick J. Wong Reported-by: Amit Sahrawat Signed-off-by: Namjae Jeon Signed-off-by: Ashish Sangwan --- fs/ext4/ialloc.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) (limited to 'fs/ext4/ialloc.c') diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c index 0ee59a6644e..a87455df38b 100644 --- a/fs/ext4/ialloc.c +++ b/fs/ext4/ialloc.c @@ -71,6 +71,7 @@ static unsigned ext4_init_inode_bitmap(struct super_block *sb, struct ext4_group_desc *gdp) { struct ext4_group_info *grp; + struct ext4_sb_info *sbi = EXT4_SB(sb); J_ASSERT_BH(bh, buffer_locked(bh)); /* If checksum is bad mark all blocks and inodes use to prevent @@ -78,7 +79,16 @@ static unsigned ext4_init_inode_bitmap(struct super_block *sb, if (!ext4_group_desc_csum_verify(sb, block_group, gdp)) { ext4_error(sb, "Checksum bad for group %u", block_group); grp = ext4_get_group_info(sb, block_group); + if (!EXT4_MB_GRP_BBITMAP_CORRUPT(grp)) + percpu_counter_sub(&sbi->s_freeclusters_counter, + grp->bb_free); set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT, &grp->bb_state); + if (!EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) { + int count; + count = ext4_free_inodes_count(sb, gdp); + percpu_counter_sub(&sbi->s_freeinodes_counter, + count); + } set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &grp->bb_state); return 0; } @@ -116,6 +126,7 @@ ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group) struct buffer_head *bh = NULL; ext4_fsblk_t bitmap_blk; struct ext4_group_info *grp; + struct ext4_sb_info *sbi = EXT4_SB(sb); desc = ext4_get_group_desc(sb, block_group, NULL); if (!desc) @@ -185,6 +196,12 @@ verify: ext4_error(sb, "Corrupt inode bitmap - block_group = %u, " "inode_bitmap = %llu", block_group, bitmap_blk); grp = ext4_get_group_info(sb, block_group); + if (!EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) { + int count; + count = ext4_free_inodes_count(sb, desc); + percpu_counter_sub(&sbi->s_freeinodes_counter, + count); + } set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &grp->bb_state); return NULL; } @@ -321,6 +338,12 @@ out: fatal = err; } else { ext4_error(sb, "bit already cleared for inode %lu", ino); + if (!EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) { + int count; + count = ext4_free_inodes_count(sb, gdp); + percpu_counter_sub(&sbi->s_freeinodes_counter, + count); + } set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &grp->bb_state); } -- cgit v1.2.3-70-g09d2 From 61c219f5814277ecb71d64cb30297028d6665979 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Sat, 5 Jul 2014 16:28:35 -0400 Subject: ext4: fix unjournalled bg descriptor while initializing inode bitmap The first time that we allocate from an uninitialized inode allocation bitmap, if the block allocation bitmap is also uninitalized, we need to get write access to the block group descriptor before we start modifying the block group descriptor flags and updating the free block count, etc. Otherwise, there is the potential of a bad journal checksum (if journal checksums are enabled), and of the file system becoming inconsistent if we crash at exactly the wrong time. Signed-off-by: Theodore Ts'o Cc: stable@vger.kernel.org --- fs/ext4/ialloc.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) (limited to 'fs/ext4/ialloc.c') diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c index a87455df38b..0840bf321cd 100644 --- a/fs/ext4/ialloc.c +++ b/fs/ext4/ialloc.c @@ -874,6 +874,13 @@ got: goto out; } + BUFFER_TRACE(group_desc_bh, "get_write_access"); + err = ext4_journal_get_write_access(handle, group_desc_bh); + if (err) { + ext4_std_error(sb, err); + goto out; + } + /* We may have to initialize the block bitmap if it isn't already */ if (ext4_has_group_desc_csum(sb) && gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) { @@ -910,13 +917,6 @@ got: } } - BUFFER_TRACE(group_desc_bh, "get_write_access"); - err = ext4_journal_get_write_access(handle, group_desc_bh); - if (err) { - ext4_std_error(sb, err); - goto out; - } - /* Update the relevant bg descriptor fields */ if (ext4_has_group_desc_csum(sb)) { int free; -- cgit v1.2.3-70-g09d2 From bf40c92635d63fcc574c52649f7cda13e0418ac1 Mon Sep 17 00:00:00 2001 From: Namjae Jeon Date: Sat, 12 Jul 2014 16:11:42 -0400 Subject: ext4: fix potential null pointer dereference in ext4_free_inode Fix potential null pointer dereferencing problem caused by e43bb4e612 ("ext4: decrement free clusters/inodes counters when block group declared bad") Reported-by: Dan Carpenter Signed-off-by: Namjae Jeon Signed-off-by: Ashish Sangwan Signed-off-by: Theodore Ts'o Reviewed-by: Lukas Czerner --- fs/ext4/ialloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/ext4/ialloc.c') diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c index 0840bf321cd..5b87fc36aab 100644 --- a/fs/ext4/ialloc.c +++ b/fs/ext4/ialloc.c @@ -338,7 +338,7 @@ out: fatal = err; } else { ext4_error(sb, "bit already cleared for inode %lu", ino); - if (!EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) { + if (gdp && !EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) { int count; count = ext4_free_inodes_count(sb, gdp); percpu_counter_sub(&sbi->s_freeinodes_counter, -- cgit v1.2.3-70-g09d2