Re: [PATCH 3/8] staging: erofs: add error handling for xattr submodule
> But it is better to fix them in an independent patch. :) Yah. Of course. This was completely unrelated. regards, dan carpenter
Re: [PATCH 3/8] staging: erofs: add error handling for xattr submodule
Hi Dan, On 2018/8/13 20:25, Dan Carpenter wrote: > On Mon, Aug 13, 2018 at 08:17:27PM +0800, Gao Xiang wrote: >>> /* we assume that ofs is aligned with 4 bytes */ >>> it->ofs = EROFS_XATTR_ALIGN(it->ofs); >>> return err; >>> > This might be cleaner if we wrote: > > return (err < 0) ? error : 0; > > The callers all treate zero and one the same so there isn't any reason > to propogate the 1 back. > Thanks, I will recheck all callers and fix as you suggested. But it is better to fix them in an independent patch. :) I will send a new patch later. Thanks, Gao Xiang > regards, > dan carpenter >
Re: [PATCH 3/8] staging: erofs: add error handling for xattr submodule
On 2018/8/13 20:17, Gao Xiang wrote: >> Generally the rule on likely/unlikely is that they hurt readability so >> we should only add them if it makes a difference in benchmarking. >> > > In my opinion, return values other than 0 and ENOATTR(ENODATA) rarely happens, > it should be in the slow path... Hi Dan, thanks for the comments. IMO, we should check and clean up all likely/unlikely in erofs, to make sure they are used in the right place. Thanks,
Re: [PATCH 3/8] staging: erofs: add error handling for xattr submodule
Hi Dan, On 2018/8/13 20:40, Dan Carpenter wrote: > On Mon, Aug 13, 2018 at 08:17:27PM +0800, Gao Xiang wrote: @@ -294,8 +322,11 @@ static int inline_getxattr(struct inode *inode, struct getxattr_iter *it) ret = xattr_foreach(>it, _xattr_handlers, ); if (ret >= 0) break; + + if (unlikely(ret != -ENOATTR)) /* -ENOMEM, -EIO, etc. */ >>> I have held off commenting on all the likely/unlikely annotations we >>> are adding because I don't know what the fast paths are in this code. >>> However, this is clearly an error path here, not on a fast path. >>> >>> Generally the rule on likely/unlikely is that they hurt readability so >>> we should only add them if it makes a difference in benchmarking. >>> >> In my opinion, return values other than 0 and ENOATTR(ENODATA) rarely >> happens, >> it should be in the slow path... >> > What I'm trying to say is please stop adding so many likely/unlikely > annotations. You should only add them if you have the benchmark data to > show the it really is required. > > OK, I'll follow your suggestion. I could say it is my personal code tendency(style). If you don't like it/think them useless, I will remove them all. Thanks for your suggestion. Thanks, Gao Xiang > regards, > dan carpenter >
Re: [PATCH 3/8] staging: erofs: add error handling for xattr submodule
On Mon, Aug 13, 2018 at 08:17:27PM +0800, Gao Xiang wrote: > >> @@ -294,8 +322,11 @@ static int inline_getxattr(struct inode *inode, > >> struct getxattr_iter *it) > >>ret = xattr_foreach(>it, _xattr_handlers, ); > >>if (ret >= 0) > >>break; > >> + > >> + if (unlikely(ret != -ENOATTR)) /* -ENOMEM, -EIO, etc. */ > > > > I have held off commenting on all the likely/unlikely annotations we > > are adding because I don't know what the fast paths are in this code. > > However, this is clearly an error path here, not on a fast path. > > > > Generally the rule on likely/unlikely is that they hurt readability so > > we should only add them if it makes a difference in benchmarking. > > > > In my opinion, return values other than 0 and ENOATTR(ENODATA) rarely happens, > it should be in the slow path... > What I'm trying to say is please stop adding so many likely/unlikely annotations. You should only add them if you have the benchmark data to show the it really is required. regards, dan carpenter
Re: [PATCH 3/8] staging: erofs: add error handling for xattr submodule
On Mon, Aug 13, 2018 at 08:17:27PM +0800, Gao Xiang wrote: > > /* we assume that ofs is aligned with 4 bytes */ > > it->ofs = EROFS_XATTR_ALIGN(it->ofs); > > return err; > > This might be cleaner if we wrote: return (err < 0) ? error : 0; The callers all treate zero and one the same so there isn't any reason to propogate the 1 back. regards, dan carpenter
Re: [PATCH 3/8] staging: erofs: add error handling for xattr submodule
Hi Xiang,
On 2018/8/13 10:36, Gao Xiang wrote:
> Hi Chao,
>
> On 2018/8/13 10:00, Chao Yu wrote:
>> On 2018/8/12 22:01, Chao Yu wrote:
>>> From: Gao Xiang
>>>
>>> This patch enhances the missing error handling code for
>>> xattr submodule, which improves the stability for the rare cases.
>>>
>>> Signed-off-by: Gao Xiang
>>> Reviewed-by: Chao Yu
>>> Signed-off-by: Chao Yu
>>> ---
>>> drivers/staging/erofs/internal.h | 6 +-
>>> drivers/staging/erofs/xattr.c| 120 ---
>>> 2 files changed, 83 insertions(+), 43 deletions(-)
>>>
>>> diff --git a/drivers/staging/erofs/internal.h
>>> b/drivers/staging/erofs/internal.h
>>> index a756abeff7e9..8951e01216e3 100644
>>> --- a/drivers/staging/erofs/internal.h
>>> +++ b/drivers/staging/erofs/internal.h
>>> @@ -485,10 +485,10 @@ struct erofs_map_blocks_iter {
>>>
>>>
>>> static inline struct page *
>>> -erofs_get_inline_page_nofail(struct inode *inode,
>>> -erofs_blk_t blkaddr)
>>> +erofs_get_inline_page(struct inode *inode,
>>> + erofs_blk_t blkaddr)
>>> {
>>> - return erofs_get_meta_page_nofail(inode->i_sb,
>>> + return erofs_get_meta_page(inode->i_sb,
>>> blkaddr, S_ISDIR(inode->i_mode));
>>> }
>>>
>>> diff --git a/drivers/staging/erofs/xattr.c b/drivers/staging/erofs/xattr.c
>>> index 2593c856b079..1b5815fc70db 100644
>>> --- a/drivers/staging/erofs/xattr.c
>>> +++ b/drivers/staging/erofs/xattr.c
>>> @@ -24,16 +24,25 @@ struct xattr_iter {
>>>
>>> static inline void xattr_iter_end(struct xattr_iter *it, bool atomic)
>>> {
>>> - /* only init_inode_xattrs use non-atomic once */
>>> + /* the only user of kunmap() is 'init_inode_xattrs' */
>>> if (unlikely(!atomic))
>>> kunmap(it->page);
>>> else
>>> kunmap_atomic(it->kaddr);
>>> +
>>> unlock_page(it->page);
>>> put_page(it->page);
>>> }
>>>
>>> -static void init_inode_xattrs(struct inode *inode)
>>> +static inline void xattr_iter_end_final(struct xattr_iter *it)
>>> +{
>>> + if (unlikely(it->page == NULL))
>>> + return;
>>> +
>>> + xattr_iter_end(it, true);
>>> +}
>>> +
>>> +static int init_inode_xattrs(struct inode *inode)
>>> {
>>> struct xattr_iter it;
>>> unsigned i;
>>> @@ -44,7 +53,7 @@ static void init_inode_xattrs(struct inode *inode)
>>> bool atomic_map;
>>>
>>> if (likely(inode_has_inited_xattr(inode)))
>>> - return;
>>> + return 0;
>>>
>>> vi = EROFS_V(inode);
>>> BUG_ON(!vi->xattr_isize);
>>> @@ -54,8 +63,9 @@ static void init_inode_xattrs(struct inode *inode)
>>> it.blkaddr = erofs_blknr(iloc(sbi, vi->nid) + vi->inode_isize);
>>> it.ofs = erofs_blkoff(iloc(sbi, vi->nid) + vi->inode_isize);
>>>
>>> - it.page = erofs_get_inline_page_nofail(inode, it.blkaddr);
>>> - BUG_ON(IS_ERR(it.page));
>>> + it.page = erofs_get_inline_page(inode, it.blkaddr);
>>> + if (IS_ERR(it.page))
>>> + return PTR_ERR(it.page);
>>>
>>> /* read in shared xattr array (non-atomic, see kmalloc below) */
>>> it.kaddr = kmap(it.page);
>>> @@ -64,9 +74,12 @@ static void init_inode_xattrs(struct inode *inode)
>>> ih = (struct erofs_xattr_ibody_header *)(it.kaddr + it.ofs);
>>>
>>> vi->xattr_shared_count = ih->h_shared_count;
>>> - vi->xattr_shared_xattrs = (unsigned *)kmalloc_array(
>>> - vi->xattr_shared_count, sizeof(unsigned),
>>> - GFP_KERNEL | __GFP_NOFAIL);
>>> + vi->xattr_shared_xattrs = kmalloc_array(vi->xattr_shared_count,
>>> + sizeof(unsigned), GFP_KERNEL);
>>> + if (unlikely(vi->xattr_shared_xattrs == NULL)) {
>>> + xattr_iter_end(, atomic_map);
>>> + return -ENOMEM;
>>> + }
>>>
>>> /* let's skip ibody header */
>>> it.ofs += sizeof(struct erofs_xattr_ibody_header);
>>> @@ -77,9 +90,10 @@ static void init_inode_xattrs(struct inode *inode)
>>> BUG_ON(it.ofs != EROFS_BLKSIZ);
>>> xattr_iter_end(, atomic_map);
>>>
>>> - it.page = erofs_get_meta_page_nofail(sb,
>>> + it.page = erofs_get_meta_page(sb,
>>> ++it.blkaddr, S_ISDIR(inode->i_mode));
>>> - BUG_ON(IS_ERR(it.page));
>>> + if (IS_ERR(it.page))
>>> + return PTR_ERR(it.page);
>>>
>>> it.kaddr = kmap_atomic(it.page);
>>> atomic_map = true;
>>> @@ -92,6 +106,7 @@ static void init_inode_xattrs(struct inode *inode)
>>> xattr_iter_end(, atomic_map);
>>>
>>> inode_set_inited_xattr(inode);
>>> + return 0;
>>> }
>>>
>>> struct xattr_iter_handlers {
>>> @@ -101,19 +116,24 @@ struct xattr_iter_handlers {
>>> void (*value)(struct xattr_iter *, unsigned, char *, unsigned);
>>> };
>>>
>>> -static void xattr_iter_fixup(struct xattr_iter *it)
>>> +static inline int xattr_iter_fixup(struct xattr_iter
Re: [PATCH 3/8] staging: erofs: add error handling for xattr submodule
Hi Chao,
On 2018/8/13 10:00, Chao Yu wrote:
> On 2018/8/12 22:01, Chao Yu wrote:
>> From: Gao Xiang
>>
>> This patch enhances the missing error handling code for
>> xattr submodule, which improves the stability for the rare cases.
>>
>> Signed-off-by: Gao Xiang
>> Reviewed-by: Chao Yu
>> Signed-off-by: Chao Yu
>> ---
>> drivers/staging/erofs/internal.h | 6 +-
>> drivers/staging/erofs/xattr.c| 120 ---
>> 2 files changed, 83 insertions(+), 43 deletions(-)
>>
>> diff --git a/drivers/staging/erofs/internal.h
>> b/drivers/staging/erofs/internal.h
>> index a756abeff7e9..8951e01216e3 100644
>> --- a/drivers/staging/erofs/internal.h
>> +++ b/drivers/staging/erofs/internal.h
>> @@ -485,10 +485,10 @@ struct erofs_map_blocks_iter {
>>
>>
>> static inline struct page *
>> -erofs_get_inline_page_nofail(struct inode *inode,
>> - erofs_blk_t blkaddr)
>> +erofs_get_inline_page(struct inode *inode,
>> + erofs_blk_t blkaddr)
>> {
>> -return erofs_get_meta_page_nofail(inode->i_sb,
>> +return erofs_get_meta_page(inode->i_sb,
>> blkaddr, S_ISDIR(inode->i_mode));
>> }
>>
>> diff --git a/drivers/staging/erofs/xattr.c b/drivers/staging/erofs/xattr.c
>> index 2593c856b079..1b5815fc70db 100644
>> --- a/drivers/staging/erofs/xattr.c
>> +++ b/drivers/staging/erofs/xattr.c
>> @@ -24,16 +24,25 @@ struct xattr_iter {
>>
>> static inline void xattr_iter_end(struct xattr_iter *it, bool atomic)
>> {
>> -/* only init_inode_xattrs use non-atomic once */
>> +/* the only user of kunmap() is 'init_inode_xattrs' */
>> if (unlikely(!atomic))
>> kunmap(it->page);
>> else
>> kunmap_atomic(it->kaddr);
>> +
>> unlock_page(it->page);
>> put_page(it->page);
>> }
>>
>> -static void init_inode_xattrs(struct inode *inode)
>> +static inline void xattr_iter_end_final(struct xattr_iter *it)
>> +{
>> +if (unlikely(it->page == NULL))
>> +return;
>> +
>> +xattr_iter_end(it, true);
>> +}
>> +
>> +static int init_inode_xattrs(struct inode *inode)
>> {
>> struct xattr_iter it;
>> unsigned i;
>> @@ -44,7 +53,7 @@ static void init_inode_xattrs(struct inode *inode)
>> bool atomic_map;
>>
>> if (likely(inode_has_inited_xattr(inode)))
>> -return;
>> +return 0;
>>
>> vi = EROFS_V(inode);
>> BUG_ON(!vi->xattr_isize);
>> @@ -54,8 +63,9 @@ static void init_inode_xattrs(struct inode *inode)
>> it.blkaddr = erofs_blknr(iloc(sbi, vi->nid) + vi->inode_isize);
>> it.ofs = erofs_blkoff(iloc(sbi, vi->nid) + vi->inode_isize);
>>
>> -it.page = erofs_get_inline_page_nofail(inode, it.blkaddr);
>> -BUG_ON(IS_ERR(it.page));
>> +it.page = erofs_get_inline_page(inode, it.blkaddr);
>> +if (IS_ERR(it.page))
>> +return PTR_ERR(it.page);
>>
>> /* read in shared xattr array (non-atomic, see kmalloc below) */
>> it.kaddr = kmap(it.page);
>> @@ -64,9 +74,12 @@ static void init_inode_xattrs(struct inode *inode)
>> ih = (struct erofs_xattr_ibody_header *)(it.kaddr + it.ofs);
>>
>> vi->xattr_shared_count = ih->h_shared_count;
>> -vi->xattr_shared_xattrs = (unsigned *)kmalloc_array(
>> -vi->xattr_shared_count, sizeof(unsigned),
>> -GFP_KERNEL | __GFP_NOFAIL);
>> +vi->xattr_shared_xattrs = kmalloc_array(vi->xattr_shared_count,
>> +sizeof(unsigned), GFP_KERNEL);
>> +if (unlikely(vi->xattr_shared_xattrs == NULL)) {
>> +xattr_iter_end(, atomic_map);
>> +return -ENOMEM;
>> +}
>>
>> /* let's skip ibody header */
>> it.ofs += sizeof(struct erofs_xattr_ibody_header);
>> @@ -77,9 +90,10 @@ static void init_inode_xattrs(struct inode *inode)
>> BUG_ON(it.ofs != EROFS_BLKSIZ);
>> xattr_iter_end(, atomic_map);
>>
>> -it.page = erofs_get_meta_page_nofail(sb,
>> +it.page = erofs_get_meta_page(sb,
>> ++it.blkaddr, S_ISDIR(inode->i_mode));
>> -BUG_ON(IS_ERR(it.page));
>> +if (IS_ERR(it.page))
>> +return PTR_ERR(it.page);
>>
>> it.kaddr = kmap_atomic(it.page);
>> atomic_map = true;
>> @@ -92,6 +106,7 @@ static void init_inode_xattrs(struct inode *inode)
>> xattr_iter_end(, atomic_map);
>>
>> inode_set_inited_xattr(inode);
>> +return 0;
>> }
>>
>> struct xattr_iter_handlers {
>> @@ -101,19 +116,24 @@ struct xattr_iter_handlers {
>> void (*value)(struct xattr_iter *, unsigned, char *, unsigned);
>> };
>>
>> -static void xattr_iter_fixup(struct xattr_iter *it)
>> +static inline int xattr_iter_fixup(struct xattr_iter *it)
>> {
>> -if (unlikely(it->ofs >= EROFS_BLKSIZ)) {
>> -xattr_iter_end(it, true);
>> +if
Re: [PATCH 3/8] staging: erofs: add error handling for xattr submodule
On 2018/8/12 22:01, Chao Yu wrote:
> From: Gao Xiang
>
> This patch enhances the missing error handling code for
> xattr submodule, which improves the stability for the rare cases.
>
> Signed-off-by: Gao Xiang
> Reviewed-by: Chao Yu
> Signed-off-by: Chao Yu
> ---
> drivers/staging/erofs/internal.h | 6 +-
> drivers/staging/erofs/xattr.c| 120 ---
> 2 files changed, 83 insertions(+), 43 deletions(-)
>
> diff --git a/drivers/staging/erofs/internal.h
> b/drivers/staging/erofs/internal.h
> index a756abeff7e9..8951e01216e3 100644
> --- a/drivers/staging/erofs/internal.h
> +++ b/drivers/staging/erofs/internal.h
> @@ -485,10 +485,10 @@ struct erofs_map_blocks_iter {
>
>
> static inline struct page *
> -erofs_get_inline_page_nofail(struct inode *inode,
> - erofs_blk_t blkaddr)
> +erofs_get_inline_page(struct inode *inode,
> + erofs_blk_t blkaddr)
> {
> - return erofs_get_meta_page_nofail(inode->i_sb,
> + return erofs_get_meta_page(inode->i_sb,
> blkaddr, S_ISDIR(inode->i_mode));
> }
>
> diff --git a/drivers/staging/erofs/xattr.c b/drivers/staging/erofs/xattr.c
> index 2593c856b079..1b5815fc70db 100644
> --- a/drivers/staging/erofs/xattr.c
> +++ b/drivers/staging/erofs/xattr.c
> @@ -24,16 +24,25 @@ struct xattr_iter {
>
> static inline void xattr_iter_end(struct xattr_iter *it, bool atomic)
> {
> - /* only init_inode_xattrs use non-atomic once */
> + /* the only user of kunmap() is 'init_inode_xattrs' */
> if (unlikely(!atomic))
> kunmap(it->page);
> else
> kunmap_atomic(it->kaddr);
> +
> unlock_page(it->page);
> put_page(it->page);
> }
>
> -static void init_inode_xattrs(struct inode *inode)
> +static inline void xattr_iter_end_final(struct xattr_iter *it)
> +{
> + if (unlikely(it->page == NULL))
> + return;
> +
> + xattr_iter_end(it, true);
> +}
> +
> +static int init_inode_xattrs(struct inode *inode)
> {
> struct xattr_iter it;
> unsigned i;
> @@ -44,7 +53,7 @@ static void init_inode_xattrs(struct inode *inode)
> bool atomic_map;
>
> if (likely(inode_has_inited_xattr(inode)))
> - return;
> + return 0;
>
> vi = EROFS_V(inode);
> BUG_ON(!vi->xattr_isize);
> @@ -54,8 +63,9 @@ static void init_inode_xattrs(struct inode *inode)
> it.blkaddr = erofs_blknr(iloc(sbi, vi->nid) + vi->inode_isize);
> it.ofs = erofs_blkoff(iloc(sbi, vi->nid) + vi->inode_isize);
>
> - it.page = erofs_get_inline_page_nofail(inode, it.blkaddr);
> - BUG_ON(IS_ERR(it.page));
> + it.page = erofs_get_inline_page(inode, it.blkaddr);
> + if (IS_ERR(it.page))
> + return PTR_ERR(it.page);
>
> /* read in shared xattr array (non-atomic, see kmalloc below) */
> it.kaddr = kmap(it.page);
> @@ -64,9 +74,12 @@ static void init_inode_xattrs(struct inode *inode)
> ih = (struct erofs_xattr_ibody_header *)(it.kaddr + it.ofs);
>
> vi->xattr_shared_count = ih->h_shared_count;
> - vi->xattr_shared_xattrs = (unsigned *)kmalloc_array(
> - vi->xattr_shared_count, sizeof(unsigned),
> - GFP_KERNEL | __GFP_NOFAIL);
> + vi->xattr_shared_xattrs = kmalloc_array(vi->xattr_shared_count,
> + sizeof(unsigned), GFP_KERNEL);
> + if (unlikely(vi->xattr_shared_xattrs == NULL)) {
> + xattr_iter_end(, atomic_map);
> + return -ENOMEM;
> + }
>
> /* let's skip ibody header */
> it.ofs += sizeof(struct erofs_xattr_ibody_header);
> @@ -77,9 +90,10 @@ static void init_inode_xattrs(struct inode *inode)
> BUG_ON(it.ofs != EROFS_BLKSIZ);
> xattr_iter_end(, atomic_map);
>
> - it.page = erofs_get_meta_page_nofail(sb,
> + it.page = erofs_get_meta_page(sb,
> ++it.blkaddr, S_ISDIR(inode->i_mode));
> - BUG_ON(IS_ERR(it.page));
> + if (IS_ERR(it.page))
> + return PTR_ERR(it.page);
>
> it.kaddr = kmap_atomic(it.page);
> atomic_map = true;
> @@ -92,6 +106,7 @@ static void init_inode_xattrs(struct inode *inode)
> xattr_iter_end(, atomic_map);
>
> inode_set_inited_xattr(inode);
> + return 0;
> }
>
> struct xattr_iter_handlers {
> @@ -101,19 +116,24 @@ struct xattr_iter_handlers {
> void (*value)(struct xattr_iter *, unsigned, char *, unsigned);
> };
>
> -static void xattr_iter_fixup(struct xattr_iter *it)
> +static inline int xattr_iter_fixup(struct xattr_iter *it)
> {
> - if (unlikely(it->ofs >= EROFS_BLKSIZ)) {
> - xattr_iter_end(it, true);
> + if (likely(it->ofs < EROFS_BLKSIZ))
> + return 0;
>
> - it->blkaddr += erofs_blknr(it->ofs);
> -
