From 19482792113fa1dc419f9bc7b04b9dbdaa5256fd Mon Sep 17 00:00:00 2001 From: Kemeng Shi Date: Wed, 14 Jun 2023 06:50:25 +0800 Subject: Revert "ext4: remove unnecessary check in ext4_bg_num_gdb_nometa" This reverts commit ad3f09be6cfe332be8ff46c78e6ec0f8839107aa. The reverted commit was intended to simpfy the code to get group descriptor block number in non-meta block group by assuming s_gdb_count is block number used for all non-meta block group descriptors. However s_gdb_count is block number used for all meta *and* non-meta group descriptors. So s_gdb_group will be > actual group descriptor block number used for all non-meta block group which should be "total non-meta block group" / "group descriptors per block", e.g. s_first_meta_bg. Signed-off-by: Kemeng Shi Link: https://lore.kernel.org/r/20230613225025.3859522-1-shikemeng@huaweicloud.com Fixes: ad3f09be6cfe ("ext4: remove unnecessary check in ext4_bg_num_gdb_nometa") Cc: stable@kernel.org Signed-off-by: Theodore Ts'o --- fs/ext4/balloc.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'fs') diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c index c1edde817be8..09c75a3127c7 100644 --- a/fs/ext4/balloc.c +++ b/fs/ext4/balloc.c @@ -886,7 +886,10 @@ static unsigned long ext4_bg_num_gdb_nometa(struct super_block *sb, if (!ext4_bg_has_super(sb, group)) return 0; - return EXT4_SB(sb)->s_gdb_count; + if (ext4_has_feature_meta_bg(sb)) + return le32_to_cpu(EXT4_SB(sb)->s_es->s_first_meta_bg); + else + return EXT4_SB(sb)->s_gdb_count; } /** -- cgit v1.2.3 From f451fd97dd2b78f286379203a47d9d295c467255 Mon Sep 17 00:00:00 2001 From: "Fabio M. De Francesco" Date: Wed, 14 Jun 2023 12:02:55 +0200 Subject: ext4: drop the call to ext4_error() from ext4_get_group_info() A recent patch added a call to ext4_error() which is problematic since some callers of the ext4_get_group_info() function may be holding a spinlock, whereas ext4_error() must never be called in atomic context. This triggered a report from Syzbot: "BUG: sleeping function called from invalid context in ext4_update_super" (see the link below). Therefore, drop the call to ext4_error() from ext4_get_group_info(). In the meantime use eight characters tabs instead of nine characters ones. Reported-by: syzbot+4acc7d910e617b360859@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/00000000000070575805fdc6cdb2@google.com/ Fixes: 5354b2af3406 ("ext4: allow ext4_get_group_info() to fail") Suggested-by: Theodore Ts'o Signed-off-by: Fabio M. De Francesco Link: https://lore.kernel.org/r/20230614100446.14337-1-fmdefrancesco@gmail.com --- fs/ext4/balloc.c | 20 +++++++++----------- 1 file changed, 9 insertions(+), 11 deletions(-) (limited to 'fs') diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c index 09c75a3127c7..1f72f977c6db 100644 --- a/fs/ext4/balloc.c +++ b/fs/ext4/balloc.c @@ -324,17 +324,15 @@ static ext4_fsblk_t ext4_valid_block_bitmap_padding(struct super_block *sb, struct ext4_group_info *ext4_get_group_info(struct super_block *sb, ext4_group_t group) { - struct ext4_group_info **grp_info; - long indexv, indexh; - - if (unlikely(group >= EXT4_SB(sb)->s_groups_count)) { - ext4_error(sb, "invalid group %u", group); - return NULL; - } - indexv = group >> (EXT4_DESC_PER_BLOCK_BITS(sb)); - indexh = group & ((EXT4_DESC_PER_BLOCK(sb)) - 1); - grp_info = sbi_array_rcu_deref(EXT4_SB(sb), s_group_info, indexv); - return grp_info[indexh]; + struct ext4_group_info **grp_info; + long indexv, indexh; + + if (unlikely(group >= EXT4_SB(sb)->s_groups_count)) + return NULL; + indexv = group >> (EXT4_DESC_PER_BLOCK_BITS(sb)); + indexh = group & ((EXT4_DESC_PER_BLOCK(sb)) - 1); + grp_info = sbi_array_rcu_deref(EXT4_SB(sb), s_group_info, indexv); + return grp_info[indexh]; } /* -- cgit v1.2.3