| Message ID | 20240126085716.1363019-8-libaokun1@huawei.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | ext4: avoid sysfs variables overflow causing BUG_ON/SOOB | expand |
On 2024/1/26 16:57, Baokun Li wrote: > The max_zeroout is of type int and the s_extent_max_zeroout_kb is of > type uint, and the s_extent_max_zeroout_kb can be freely modified via > the sysfs interface. When the block size is 1024, max_zeroout may > overflow, so declare it as unsigned int to avoid overflow. > > Signed-off-by: Baokun Li <libaokun1@huawei.com> Looks good to me. Reviewed-by: Zhang Yi <yi.zhang@huawei.com> > --- > fs/ext4/extents.c | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) > > diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c > index 01299b55a567..8653b13e8248 100644 > --- a/fs/ext4/extents.c > +++ b/fs/ext4/extents.c > @@ -3425,10 +3425,8 @@ static int ext4_ext_convert_to_initialized(handle_t *handle, > struct ext4_extent zero_ex1, zero_ex2; > struct ext4_extent *ex, *abut_ex; > ext4_lblk_t ee_block, eof_block; > - unsigned int ee_len, depth, map_len = map->m_len; > - int allocated = 0, max_zeroout = 0; > - int err = 0; > - int split_flag = EXT4_EXT_DATA_VALID2; > + unsigned int ee_len, depth, map_len = map->m_len, max_zeroout = 0; > + int err = 0, allocated = 0, split_flag = EXT4_EXT_DATA_VALID2; > > ext_debug(inode, "logical block %llu, max_blocks %u\n", > (unsigned long long)map->m_lblk, map_len); >
On Fri 26-01-24 16:57:16, Baokun Li wrote: > The max_zeroout is of type int and the s_extent_max_zeroout_kb is of > type uint, and the s_extent_max_zeroout_kb can be freely modified via > the sysfs interface. When the block size is 1024, max_zeroout may > overflow, so declare it as unsigned int to avoid overflow. > > Signed-off-by: Baokun Li <libaokun1@huawei.com> > --- > fs/ext4/extents.c | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) > > diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c > index 01299b55a567..8653b13e8248 100644 > --- a/fs/ext4/extents.c > +++ b/fs/ext4/extents.c > @@ -3425,10 +3425,8 @@ static int ext4_ext_convert_to_initialized(handle_t *handle, > struct ext4_extent zero_ex1, zero_ex2; > struct ext4_extent *ex, *abut_ex; > ext4_lblk_t ee_block, eof_block; > - unsigned int ee_len, depth, map_len = map->m_len; > - int allocated = 0, max_zeroout = 0; > - int err = 0; > - int split_flag = EXT4_EXT_DATA_VALID2; > + unsigned int ee_len, depth, map_len = map->m_len, max_zeroout = 0; > + int err = 0, allocated = 0, split_flag = EXT4_EXT_DATA_VALID2; Honestly, I prefer if we keep unrelated variables on different lines, especially when they have initializers. I find the code more readable that way. So in this case: int err = 0; int split_flag = EXT4_EXT_DATA_VALID2; int allocated = 0; unsigned int max_zeroout = 0; But otherwise the fix looks good! Honza
On 2024/2/14 0:38, Jan Kara wrote: > On Fri 26-01-24 16:57:16, Baokun Li wrote: >> The max_zeroout is of type int and the s_extent_max_zeroout_kb is of >> type uint, and the s_extent_max_zeroout_kb can be freely modified via >> the sysfs interface. When the block size is 1024, max_zeroout may >> overflow, so declare it as unsigned int to avoid overflow. >> >> Signed-off-by: Baokun Li <libaokun1@huawei.com> >> --- >> fs/ext4/extents.c | 6 ++---- >> 1 file changed, 2 insertions(+), 4 deletions(-) >> >> diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c >> index 01299b55a567..8653b13e8248 100644 >> --- a/fs/ext4/extents.c >> +++ b/fs/ext4/extents.c >> @@ -3425,10 +3425,8 @@ static int ext4_ext_convert_to_initialized(handle_t *handle, >> struct ext4_extent zero_ex1, zero_ex2; >> struct ext4_extent *ex, *abut_ex; >> ext4_lblk_t ee_block, eof_block; >> - unsigned int ee_len, depth, map_len = map->m_len; >> - int allocated = 0, max_zeroout = 0; >> - int err = 0; >> - int split_flag = EXT4_EXT_DATA_VALID2; >> + unsigned int ee_len, depth, map_len = map->m_len, max_zeroout = 0; >> + int err = 0, allocated = 0, split_flag = EXT4_EXT_DATA_VALID2; > Honestly, I prefer if we keep unrelated variables on different lines, > especially when they have initializers. I find the code more readable that > way. So in this case: > > int err = 0; > int split_flag = EXT4_EXT_DATA_VALID2; > int allocated = 0; > unsigned int max_zeroout = 0; > > But otherwise the fix looks good! > > Honza Totally agree! I will replace it in the next version. Thanks!
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 01299b55a567..8653b13e8248 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -3425,10 +3425,8 @@ static int ext4_ext_convert_to_initialized(handle_t *handle, struct ext4_extent zero_ex1, zero_ex2; struct ext4_extent *ex, *abut_ex; ext4_lblk_t ee_block, eof_block; - unsigned int ee_len, depth, map_len = map->m_len; - int allocated = 0, max_zeroout = 0; - int err = 0; - int split_flag = EXT4_EXT_DATA_VALID2; + unsigned int ee_len, depth, map_len = map->m_len, max_zeroout = 0; + int err = 0, allocated = 0, split_flag = EXT4_EXT_DATA_VALID2; ext_debug(inode, "logical block %llu, max_blocks %u\n", (unsigned long long)map->m_lblk, map_len);
The max_zeroout is of type int and the s_extent_max_zeroout_kb is of type uint, and the s_extent_max_zeroout_kb can be freely modified via the sysfs interface. When the block size is 1024, max_zeroout may overflow, so declare it as unsigned int to avoid overflow. Signed-off-by: Baokun Li <libaokun1@huawei.com> --- fs/ext4/extents.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-)