2013-09-13 13:28:11

by Chao Yu

[permalink] [raw]
Subject: [f2fs-dev][PATCH RESEND] f2fs: avoid allocating failure in bio_alloc

This patch add macro MAX_BIO_BLOCKS to limit value of npages in
f2fs_bio_alloc,
it can avoid allocating failure in bio_alloc caused by npages is larger than
UIO_MAXIOV.

Signed-off-by: Yu Chao <[email protected]>
---
fs/f2fs/segment.c | 4 +++-
fs/f2fs/segment.h | 3 +++
2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 09af9c7..bd79bbe 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -657,6 +657,7 @@ static void submit_write_page(struct f2fs_sb_info *sbi,
struct page *page,
block_t blk_addr, enum page_type type)
{
struct block_device *bdev = sbi->sb->s_bdev;
+ int bio_blocks;

verify_block_addr(sbi, blk_addr);

@@ -676,7 +677,8 @@ retry:
goto retry;
}

- sbi->bio[type] = f2fs_bio_alloc(bdev, max_hw_blocks(sbi));
+ bio_blocks = MAX_BIO_BLOCKS(max_hw_blocks(sbi));
+ sbi->bio[type] = f2fs_bio_alloc(bdev, bio_blocks);
sbi->bio[type]->bi_sector = SECTOR_FROM_BLOCK(sbi,
blk_addr);
sbi->bio[type]->bi_private = priv;
/*
diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
index bdd10ea..6352af1 100644
--- a/fs/f2fs/segment.h
+++ b/fs/f2fs/segment.h
@@ -9,6 +9,7 @@
* published by the Free Software Foundation.
*/
#include <linux/blkdev.h>
+#include <linux/uio.h>

/* constant macro */
#define NULL_SEGNO ((unsigned int)(~0))
@@ -90,6 +91,8 @@
(blk_addr << ((sbi)->log_blocksize - F2FS_LOG_SECTOR_SIZE))
#define SECTOR_TO_BLOCK(sbi, sectors) \
(sectors >> ((sbi)->log_blocksize - F2FS_LOG_SECTOR_SIZE))
+#define MAX_BIO_BLOCKS(max_hw_blocks) \
+ (min((int)max_hw_blocks, UIO_MAXIOV))

/* during checkpoint, bio_private is used to synchronize the last bio */
struct bio_private {
---


2013-09-16 02:14:13

by Gu Zheng

[permalink] [raw]
Subject: Re: [f2fs-dev][PATCH RESEND] f2fs: avoid allocating failure in bio_alloc

Hi Chao,

On 09/13/2013 09:27 PM, Chao Yu wrote:

> This patch add macro MAX_BIO_BLOCKS to limit value of npages in
> f2fs_bio_alloc,
> it can avoid allocating failure in bio_alloc caused by npages is larger than
> UIO_MAXIOV.

As I know bio_alloc is based of *fs_bio_set* pool, without the limitation of UIO_MAXIOV,
am I missing something?

Thanks,
Gu

>
> Signed-off-by: Yu Chao <[email protected]>
> ---
> fs/f2fs/segment.c | 4 +++-
> fs/f2fs/segment.h | 3 +++
> 2 files changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
> index 09af9c7..bd79bbe 100644
> --- a/fs/f2fs/segment.c
> +++ b/fs/f2fs/segment.c
> @@ -657,6 +657,7 @@ static void submit_write_page(struct f2fs_sb_info *sbi,
> struct page *page,
> block_t blk_addr, enum page_type type)
> {
> struct block_device *bdev = sbi->sb->s_bdev;
> + int bio_blocks;
>
> verify_block_addr(sbi, blk_addr);
>
> @@ -676,7 +677,8 @@ retry:
> goto retry;
> }
>
> - sbi->bio[type] = f2fs_bio_alloc(bdev, max_hw_blocks(sbi));
> + bio_blocks = MAX_BIO_BLOCKS(max_hw_blocks(sbi));
> + sbi->bio[type] = f2fs_bio_alloc(bdev, bio_blocks);
> sbi->bio[type]->bi_sector = SECTOR_FROM_BLOCK(sbi,
> blk_addr);
> sbi->bio[type]->bi_private = priv;
> /*
> diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
> index bdd10ea..6352af1 100644
> --- a/fs/f2fs/segment.h
> +++ b/fs/f2fs/segment.h
> @@ -9,6 +9,7 @@
> * published by the Free Software Foundation.
> */
> #include <linux/blkdev.h>
> +#include <linux/uio.h>
>
> /* constant macro */
> #define NULL_SEGNO ((unsigned int)(~0))
> @@ -90,6 +91,8 @@
> (blk_addr << ((sbi)->log_blocksize - F2FS_LOG_SECTOR_SIZE))
> #define SECTOR_TO_BLOCK(sbi, sectors) \
> (sectors >> ((sbi)->log_blocksize - F2FS_LOG_SECTOR_SIZE))
> +#define MAX_BIO_BLOCKS(max_hw_blocks) \
> + (min((int)max_hw_blocks, UIO_MAXIOV))
>
> /* during checkpoint, bio_private is used to synchronize the last bio */
> struct bio_private {
> ---
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
>

2013-09-16 03:27:05

by Chao Yu

[permalink] [raw]
Subject: Re: [f2fs-dev][PATCH RESEND] f2fs: avoid allocating failure in bio_alloc

Hi Gu

> -----Original Message-----
> From: Gu Zheng [mailto:[email protected]]
> Sent: Monday, September 16, 2013 10:09 AM
> To: Chao Yu
> Cc: Kim Jaegeuk; [email protected];
> [email protected]; [email protected]; ̷??
> Subject: Re: [f2fs-dev][PATCH RESEND] f2fs: avoid allocating failure in
bio_alloc
>
> Hi Chao,
>
> On 09/13/2013 09:27 PM, Chao Yu wrote:
>
> > This patch add macro MAX_BIO_BLOCKS to limit value of npages in
> > f2fs_bio_alloc, it can avoid allocating failure in bio_alloc caused by
> > npages is larger than UIO_MAXIOV.
>
> As I know bio_alloc is based of *fs_bio_set* pool, without the limitation
of
> UIO_MAXIOV, am I missing something?

Here is the code in bio.c, fs_bio_set is as the actual parameter pass to bs
without being inited.
So it may have opportunity to return NULL in this function.
---
Bio.c
struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set
*bs)
{
......
if (!bs) {
if (nr_iovecs > UIO_MAXIOV)
return NULL;
---
I did the abnormal test: modify the max_sectors_kb in /sys/block/sdx/queue
to 32767 for a disk with f2fs format,
and I got a segfualt in f2fs_bio_alloc after the img mounted.
Is there anyting I missed?

>
> Thanks,
> Gu
>
> >
> > Signed-off-by: Yu Chao <[email protected]>
> > ---
> > fs/f2fs/segment.c | 4 +++-
> > fs/f2fs/segment.h | 3 +++
> > 2 files changed, 6 insertions(+), 1 deletion(-)
> >
> > diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c index
> > 09af9c7..bd79bbe 100644
> > --- a/fs/f2fs/segment.c
> > +++ b/fs/f2fs/segment.c
> > @@ -657,6 +657,7 @@ static void submit_write_page(struct f2fs_sb_info
> > *sbi, struct page *page,
> > block_t blk_addr, enum page_type
> type)
> > {
> > struct block_device *bdev = sbi->sb->s_bdev;
> > + int bio_blocks;
> >
> > verify_block_addr(sbi, blk_addr);
> >
> > @@ -676,7 +677,8 @@ retry:
> > goto retry;
> > }
> >
> > - sbi->bio[type] = f2fs_bio_alloc(bdev,
max_hw_blocks(sbi));
> > + bio_blocks = MAX_BIO_BLOCKS(max_hw_blocks(sbi));
> > + sbi->bio[type] = f2fs_bio_alloc(bdev, bio_blocks);
> > sbi->bio[type]->bi_sector = SECTOR_FROM_BLOCK(sbi,
> > blk_addr);
> > sbi->bio[type]->bi_private = priv;
> > /*
> > diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h index
> > bdd10ea..6352af1 100644
> > --- a/fs/f2fs/segment.h
> > +++ b/fs/f2fs/segment.h
> > @@ -9,6 +9,7 @@
> > * published by the Free Software Foundation.
> > */
> > #include <linux/blkdev.h>
> > +#include <linux/uio.h>
> >
> > /* constant macro */
> > #define NULL_SEGNO ((unsigned int)(~0))
> > @@ -90,6 +91,8 @@
> > (blk_addr << ((sbi)->log_blocksize - F2FS_LOG_SECTOR_SIZE))
> > #define SECTOR_TO_BLOCK(sbi, sectors)
> \
> > (sectors >> ((sbi)->log_blocksize - F2FS_LOG_SECTOR_SIZE))
> > +#define MAX_BIO_BLOCKS(max_hw_blocks)
> \
> > + (min((int)max_hw_blocks, UIO_MAXIOV))
> >
> > /* during checkpoint, bio_private is used to synchronize the last bio
> > */ struct bio_private {
> > ---
> >
> > --
> > To unsubscribe from this list: send the line "unsubscribe
> > linux-kernel" in the body of a message to [email protected]
> > More majordomo info at http://vger.kernel.org/majordomo-info.html
> > Please read the FAQ at http://www.tux.org/lkml/
> >

2013-09-16 04:45:20

by Gu Zheng

[permalink] [raw]
Subject: Re: [f2fs-dev][PATCH RESEND] f2fs: avoid allocating failure in bio_alloc

Hi Chao,

On 09/16/2013 11:26 AM, Chao Yu wrote:

> Hi Gu
>
>> -----Original Message-----
>> From: Gu Zheng [mailto:[email protected]]
>> Sent: Monday, September 16, 2013 10:09 AM
>> To: Chao Yu
>> Cc: Kim Jaegeuk; [email protected];
>> [email protected]; [email protected]; ̷??
>> Subject: Re: [f2fs-dev][PATCH RESEND] f2fs: avoid allocating failure in
> bio_alloc
>>
>> Hi Chao,
>>
>> On 09/13/2013 09:27 PM, Chao Yu wrote:
>>
>>> This patch add macro MAX_BIO_BLOCKS to limit value of npages in
>>> f2fs_bio_alloc, it can avoid allocating failure in bio_alloc caused by
>>> npages is larger than UIO_MAXIOV.
>>
>> As I know bio_alloc is based of *fs_bio_set* pool, without the limitation
> of
>> UIO_MAXIOV, am I missing something?
>
> Here is the code in bio.c, fs_bio_set is as the actual parameter pass to bs
> without being inited.

fs_bio_set was initiated early in the bio subsystem init.

> So it may have opportunity to return NULL in this function.

It may be, but may not be the thread you mentioned below.

> ---
> Bio.c
> struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set
> *bs)
> {
> ......
> if (!bs) {
> if (nr_iovecs > UIO_MAXIOV)
> return NULL;
> ---
> I did the abnormal test: modify the max_sectors_kb in /sys/block/sdx/queue
> to 32767 for a disk with f2fs format,
> and I got a segfualt in f2fs_bio_alloc after the img mounted.
> Is there anyting I missed?

Hmm, this change will also trigger bvec_alloc failed, did you add some traces
to debug this?

Regards,
Gu

>
>>
>> Thanks,
>> Gu
>>
>>>
>>> Signed-off-by: Yu Chao <[email protected]>
>>> ---
>>> fs/f2fs/segment.c | 4 +++-
>>> fs/f2fs/segment.h | 3 +++
>>> 2 files changed, 6 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c index
>>> 09af9c7..bd79bbe 100644
>>> --- a/fs/f2fs/segment.c
>>> +++ b/fs/f2fs/segment.c
>>> @@ -657,6 +657,7 @@ static void submit_write_page(struct f2fs_sb_info
>>> *sbi, struct page *page,
>>> block_t blk_addr, enum page_type
>> type)
>>> {
>>> struct block_device *bdev = sbi->sb->s_bdev;
>>> + int bio_blocks;
>>>
>>> verify_block_addr(sbi, blk_addr);
>>>
>>> @@ -676,7 +677,8 @@ retry:
>>> goto retry;
>>> }
>>>
>>> - sbi->bio[type] = f2fs_bio_alloc(bdev,
> max_hw_blocks(sbi));
>>> + bio_blocks = MAX_BIO_BLOCKS(max_hw_blocks(sbi));
>>> + sbi->bio[type] = f2fs_bio_alloc(bdev, bio_blocks);
>>> sbi->bio[type]->bi_sector = SECTOR_FROM_BLOCK(sbi,
>>> blk_addr);
>>> sbi->bio[type]->bi_private = priv;
>>> /*
>>> diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h index
>>> bdd10ea..6352af1 100644
>>> --- a/fs/f2fs/segment.h
>>> +++ b/fs/f2fs/segment.h
>>> @@ -9,6 +9,7 @@
>>> * published by the Free Software Foundation.
>>> */
>>> #include <linux/blkdev.h>
>>> +#include <linux/uio.h>
>>>
>>> /* constant macro */
>>> #define NULL_SEGNO ((unsigned int)(~0))
>>> @@ -90,6 +91,8 @@
>>> (blk_addr << ((sbi)->log_blocksize - F2FS_LOG_SECTOR_SIZE))
>>> #define SECTOR_TO_BLOCK(sbi, sectors)
>> \
>>> (sectors >> ((sbi)->log_blocksize - F2FS_LOG_SECTOR_SIZE))
>>> +#define MAX_BIO_BLOCKS(max_hw_blocks)
>> \
>>> + (min((int)max_hw_blocks, UIO_MAXIOV))
>>>
>>> /* during checkpoint, bio_private is used to synchronize the last bio
>>> */ struct bio_private {
>>> ---
>>>
>>> --
>>> To unsubscribe from this list: send the line "unsubscribe
>>> linux-kernel" in the body of a message to [email protected]
>>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>>> Please read the FAQ at http://www.tux.org/lkml/
>>>
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
>

2013-09-17 03:14:24

by Chao Yu

[permalink] [raw]
Subject: RE: [f2fs-dev][PATCH RESEND] f2fs: avoid allocating failure in bio_alloc

Hi Gu

> -----Original Message-----
> From: Gu Zheng [mailto:[email protected]]
> Sent: Monday, September 16, 2013 12:40 PM
> To: Chao Yu
> Cc: 'Kim Jaegeuk'; [email protected];
> [email protected]; [email protected]; '̷??'
> Subject: Re: [f2fs-dev][PATCH RESEND] f2fs: avoid allocating failure in
bio_alloc
>
> Hi Chao,
>
> On 09/16/2013 11:26 AM, Chao Yu wrote:
>
> > Hi Gu
> >
> >> -----Original Message-----
> >> From: Gu Zheng [mailto:[email protected]]
> >> Sent: Monday, September 16, 2013 10:09 AM
> >> To: Chao Yu
> >> Cc: Kim Jaegeuk; [email protected];
> >> [email protected]; [email protected]; ̷??
> >> Subject: Re: [f2fs-dev][PATCH RESEND] f2fs: avoid allocating failure
> >> in
> > bio_alloc
> >>
> >> Hi Chao,
> >>
> >> On 09/13/2013 09:27 PM, Chao Yu wrote:
> >>
> >>> This patch add macro MAX_BIO_BLOCKS to limit value of npages in
> >>> f2fs_bio_alloc, it can avoid allocating failure in bio_alloc caused
> >>> by npages is larger than UIO_MAXIOV.
> >>
> >> As I know bio_alloc is based of *fs_bio_set* pool, without the
> >> limitation
> > of
> >> UIO_MAXIOV, am I missing something?
> >
> > Here is the code in bio.c, fs_bio_set is as the actual parameter pass
> > to bs without being inited.
>
> fs_bio_set was initiated early in the bio subsystem init.
>
> > So it may have opportunity to return NULL in this function.
>
> It may be, but may not be the thread you mentioned below.
>
> > ---
> > Bio.c
> > struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct
> > bio_set
> > *bs)
> > {
> > ......
> > if (!bs) {
> > if (nr_iovecs > UIO_MAXIOV)
> > return NULL;
> > ---
> > I did the abnormal test: modify the max_sectors_kb in
> > /sys/block/sdx/queue to 32767 for a disk with f2fs format, and I got a
> > segfualt in f2fs_bio_alloc after the img mounted.
> > Is there anyting I missed?
>
> Hmm, this change will also trigger bvec_alloc failed, did you add some
traces to
> debug this?

I reviewed the code in bio_alloc, and then trace the process of bio_alloc
for verification.
It indicate that bvec_alloc() will fail on the condition that nr_iovecs is
greater than BIO_MAX_PAGES.
The patch should be updated for that.

I am sorry about the mistake in this patch, and thanks for the reviewing and
reminding.

>
> Regards,
> Gu
>
> >
> >>
> >> Thanks,
> >> Gu
> >>
> >>>
> >>> Signed-off-by: Yu Chao <[email protected]>
> >>> ---
> >>> fs/f2fs/segment.c | 4 +++-
> >>> fs/f2fs/segment.h | 3 +++
> >>> 2 files changed, 6 insertions(+), 1 deletion(-)
> >>>
> >>> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c index
> >>> 09af9c7..bd79bbe 100644
> >>> --- a/fs/f2fs/segment.c
> >>> +++ b/fs/f2fs/segment.c
> >>> @@ -657,6 +657,7 @@ static void submit_write_page(struct
> >>> f2fs_sb_info *sbi, struct page *page,
> >>> block_t blk_addr, enum page_type
> >> type)
> >>> {
> >>> struct block_device *bdev = sbi->sb->s_bdev;
> >>> + int bio_blocks;
> >>>
> >>> verify_block_addr(sbi, blk_addr);
> >>>
> >>> @@ -676,7 +677,8 @@ retry:
> >>> goto retry;
> >>> }
> >>>
> >>> - sbi->bio[type] = f2fs_bio_alloc(bdev,
> > max_hw_blocks(sbi));
> >>> + bio_blocks = MAX_BIO_BLOCKS(max_hw_blocks(sbi));
> >>> + sbi->bio[type] = f2fs_bio_alloc(bdev, bio_blocks);
> >>> sbi->bio[type]->bi_sector =
> SECTOR_FROM_BLOCK(sbi,
> >>> blk_addr);
> >>> sbi->bio[type]->bi_private = priv;
> >>> /*
> >>> diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h index
> >>> bdd10ea..6352af1 100644
> >>> --- a/fs/f2fs/segment.h
> >>> +++ b/fs/f2fs/segment.h
> >>> @@ -9,6 +9,7 @@
> >>> * published by the Free Software Foundation.
> >>> */
> >>> #include <linux/blkdev.h>
> >>> +#include <linux/uio.h>
> >>>
> >>> /* constant macro */
> >>> #define NULL_SEGNO ((unsigned int)(~0))
> >>> @@ -90,6 +91,8 @@
> >>> (blk_addr << ((sbi)->log_blocksize - F2FS_LOG_SECTOR_SIZE))
> >>> #define SECTOR_TO_BLOCK(sbi, sectors)
> >> \
> >>> (sectors >> ((sbi)->log_blocksize - F2FS_LOG_SECTOR_SIZE))
> >>> +#define MAX_BIO_BLOCKS(max_hw_blocks)
> >> \
> >>> + (min((int)max_hw_blocks, UIO_MAXIOV))
> >>>
> >>> /* during checkpoint, bio_private is used to synchronize the last
> >>> bio */ struct bio_private {
> >>> ---
> >>>
> >>> --
> >>> To unsubscribe from this list: send the line "unsubscribe
> >>> linux-kernel" in the body of a message to [email protected]
> >>> More majordomo info at http://vger.kernel.org/majordomo-info.html
> >>> Please read the FAQ at http://www.tux.org/lkml/
> >>>
> >
> >
> > --
> > To unsubscribe from this list: send the line "unsubscribe
> > linux-kernel" in the body of a message to [email protected]
> > More majordomo info at http://vger.kernel.org/majordomo-info.html
> > Please read the FAQ at http://www.tux.org/lkml/
> >
>
>
> =