From 9ccf35492b084ecbc916761a5c6f42599450f013 Mon Sep 17 00:00:00 2001 From: Jeffle Xu Date: Mon, 23 Aug 2021 14:13:58 +0800 Subject: [PATCH] ext4: fix reserved space counter leakage commit 6fed83957f21eff11c8496e9f24253b03d2bc1dc upstream. When ext4_insert_delayed block receives and recovers from an error from ext4_es_insert_delayed_block(), e.g., ENOMEM, it does not release the space it has reserved for that block insertion as it should. One effect of this bug is that s_dirtyclusters_counter is not decremented and remains incorrectly elevated until the file system has been unmounted. This can result in premature ENOSPC returns and apparent loss of free space. Another effect of this bug is that /sys/fs/ext4//delayed_allocation_blocks can remain non-zero even after syncfs has been executed on the filesystem. Besides, add check for s_dirtyclusters_counter when inode is going to be evicted and freed. s_dirtyclusters_counter can still keep non-zero until inode is written back in .evict_inode(), and thus the check is delayed to .destroy_inode(). Fixes: 51865fda28e5 ("ext4: let ext4 maintain extent status tree") Cc: stable@kernel.org Suggested-by: Gao Xiang Signed-off-by: Jeffle Xu Reviewed-by: Eric Whitney Signed-off-by: Theodore Ts'o Link: https://lore.kernel.org/r/20210823061358.84473-1-jefflexu@linux.alibaba.com Signed-off-by: Greg Kroah-Hartman --- fs/ext4/inode.c | 5 +++++ fs/ext4/super.c | 6 ++++++ 2 files changed, 11 insertions(+) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 18a5321b5ef3..63a292db7587 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -1641,6 +1641,7 @@ static int ext4_insert_delayed_block(struct inode *inode, ext4_lblk_t lblk) struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); int ret; bool allocated = false; + bool reserved = false; /* * If the cluster containing lblk is shared with a delayed, @@ -1657,6 +1658,7 @@ static int ext4_insert_delayed_block(struct inode *inode, ext4_lblk_t lblk) ret = ext4_da_reserve_space(inode); if (ret != 0) /* ENOSPC */ goto errout; + reserved = true; } else { /* bigalloc */ if (!ext4_es_scan_clu(inode, &ext4_es_is_delonly, lblk)) { if (!ext4_es_scan_clu(inode, @@ -1669,6 +1671,7 @@ static int ext4_insert_delayed_block(struct inode *inode, ext4_lblk_t lblk) ret = ext4_da_reserve_space(inode); if (ret != 0) /* ENOSPC */ goto errout; + reserved = true; } else { allocated = true; } @@ -1679,6 +1682,8 @@ static int ext4_insert_delayed_block(struct inode *inode, ext4_lblk_t lblk) } ret = ext4_es_insert_delayed_block(inode, lblk, allocated); + if (ret && reserved) + ext4_da_release_space(inode, 1); errout: return ret; diff --git a/fs/ext4/super.c b/fs/ext4/super.c index e5e896b6200a..cbeb02429671 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -1356,6 +1356,12 @@ static void ext4_destroy_inode(struct inode *inode) true); dump_stack(); } + + if (EXT4_I(inode)->i_reserved_data_blocks) + ext4_msg(inode->i_sb, KERN_ERR, + "Inode %lu (%p): i_reserved_data_blocks (%u) not cleared!", + inode->i_ino, EXT4_I(inode), + EXT4_I(inode)->i_reserved_data_blocks); } static void init_once(void *foo)