2022-02-06 13:49:39

by Ritesh Harjani

[permalink] [raw]
Subject: [PATCHv1 8/9] ext4: Add strict range checks while freeing blocks

Currently ext4_mb_clear_bb() & ext4_group_add_blocks() only checks
whether the given block ranges (which is to be freed) belongs to any FS
metadata blocks or not, of the block's respective block group.
But to detect any FS error early, it is better to add more strict
checkings in those functions which checks whether the given blocks
belongs to any critical FS metadata or not within system-zone.

Suggested-by: Jan Kara <[email protected]>
Signed-off-by: Ritesh Harjani <[email protected]>
---
fs/ext4/mballoc.c | 16 +++-------------
1 file changed, 3 insertions(+), 13 deletions(-)

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 23313963bb56..9f2b3a057918 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -5930,13 +5930,7 @@ static void ext4_mb_clear_bb(handle_t *handle, struct inode *inode,
goto error_return;
}

- if (in_range(ext4_block_bitmap(sb, gdp), block, count) ||
- in_range(ext4_inode_bitmap(sb, gdp), block, count) ||
- in_range(block, ext4_inode_table(sb, gdp),
- sbi->s_itb_per_group) ||
- in_range(block + count - 1, ext4_inode_table(sb, gdp),
- sbi->s_itb_per_group)) {
-
+ if (!ext4_inode_block_valid(inode, block, count)) {
ext4_error(sb, "Freeing blocks in system zone - "
"Block = %llu, count = %lu", block, count);
/* err = 0. ext4_std_error should be a no op */
@@ -6007,7 +6001,7 @@ static void ext4_mb_clear_bb(handle_t *handle, struct inode *inode,
NULL);
if (err && err != -EOPNOTSUPP)
ext4_msg(sb, KERN_WARNING, "discard request in"
- " group:%d block:%d count:%lu failed"
+ " group:%u block:%d count:%lu failed"
" with %d", block_group, bit, count,
err);
} else
@@ -6220,11 +6214,7 @@ int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
goto error_return;
}

- if (in_range(ext4_block_bitmap(sb, desc), block, count) ||
- in_range(ext4_inode_bitmap(sb, desc), block, count) ||
- in_range(block, ext4_inode_table(sb, desc), sbi->s_itb_per_group) ||
- in_range(block + count - 1, ext4_inode_table(sb, desc),
- sbi->s_itb_per_group)) {
+ if (!ext4_sb_block_valid(sb, NULL, block, count)) {
ext4_error(sb, "Adding blocks in system zones - "
"Block = %llu, count = %lu",
block, count);
--
2.31.1



2022-02-08 03:15:57

by Jan Kara

[permalink] [raw]
Subject: Re: [PATCHv1 8/9] ext4: Add strict range checks while freeing blocks

On Sat 05-02-22 19:39:57, Ritesh Harjani wrote:
> Currently ext4_mb_clear_bb() & ext4_group_add_blocks() only checks
> whether the given block ranges (which is to be freed) belongs to any FS
> metadata blocks or not, of the block's respective block group.
> But to detect any FS error early, it is better to add more strict
> checkings in those functions which checks whether the given blocks
> belongs to any critical FS metadata or not within system-zone.
>
> Suggested-by: Jan Kara <[email protected]>
> Signed-off-by: Ritesh Harjani <[email protected]>

Looks good. Feel free to add:

Reviewed-by: Jan Kara <[email protected]>

Honza

> ---
> fs/ext4/mballoc.c | 16 +++-------------
> 1 file changed, 3 insertions(+), 13 deletions(-)
>
> diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
> index 23313963bb56..9f2b3a057918 100644
> --- a/fs/ext4/mballoc.c
> +++ b/fs/ext4/mballoc.c
> @@ -5930,13 +5930,7 @@ static void ext4_mb_clear_bb(handle_t *handle, struct inode *inode,
> goto error_return;
> }
>
> - if (in_range(ext4_block_bitmap(sb, gdp), block, count) ||
> - in_range(ext4_inode_bitmap(sb, gdp), block, count) ||
> - in_range(block, ext4_inode_table(sb, gdp),
> - sbi->s_itb_per_group) ||
> - in_range(block + count - 1, ext4_inode_table(sb, gdp),
> - sbi->s_itb_per_group)) {
> -
> + if (!ext4_inode_block_valid(inode, block, count)) {
> ext4_error(sb, "Freeing blocks in system zone - "
> "Block = %llu, count = %lu", block, count);
> /* err = 0. ext4_std_error should be a no op */
> @@ -6007,7 +6001,7 @@ static void ext4_mb_clear_bb(handle_t *handle, struct inode *inode,
> NULL);
> if (err && err != -EOPNOTSUPP)
> ext4_msg(sb, KERN_WARNING, "discard request in"
> - " group:%d block:%d count:%lu failed"
> + " group:%u block:%d count:%lu failed"
> " with %d", block_group, bit, count,
> err);
> } else
> @@ -6220,11 +6214,7 @@ int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
> goto error_return;
> }
>
> - if (in_range(ext4_block_bitmap(sb, desc), block, count) ||
> - in_range(ext4_inode_bitmap(sb, desc), block, count) ||
> - in_range(block, ext4_inode_table(sb, desc), sbi->s_itb_per_group) ||
> - in_range(block + count - 1, ext4_inode_table(sb, desc),
> - sbi->s_itb_per_group)) {
> + if (!ext4_sb_block_valid(sb, NULL, block, count)) {
> ext4_error(sb, "Adding blocks in system zones - "
> "Block = %llu, count = %lu",
> block, count);
> --
> 2.31.1
>
--
Jan Kara <[email protected]>
SUSE Labs, CR