diff mbox series

[v3] xfs: fix ag count overflow during growfs

Message ID 20230524121041.GA4128075@ceph-admin (mailing list archive)
State Superseded, archived
Headers show
Series [v3] xfs: fix ag count overflow during growfs | expand

Commit Message

Long Li May 24, 2023, 12:10 p.m. UTC
I found a corruption during growfs:

 XFS (loop0): Internal error agbno >= mp->m_sb.sb_agblocks at line 3661 of
   file fs/xfs/libxfs/xfs_alloc.c.  Caller __xfs_free_extent+0x28e/0x3c0
 CPU: 0 PID: 573 Comm: xfs_growfs Not tainted 6.3.0-rc7-next-20230420-00001-gda8c95746257
 Call Trace:
  <TASK>
  dump_stack_lvl+0x50/0x70
  xfs_corruption_error+0x134/0x150
  __xfs_free_extent+0x2c1/0x3c0
  xfs_ag_extend_space+0x291/0x3e0
  xfs_growfs_data+0xd72/0xe90
  xfs_file_ioctl+0x5f9/0x14a0
  __x64_sys_ioctl+0x13e/0x1c0
  do_syscall_64+0x39/0x80
  entry_SYSCALL_64_after_hwframe+0x63/0xcd
 XFS (loop0): Corruption detected. Unmount and run xfs_repair
 XFS (loop0): Internal error xfs_trans_cancel at line 1097 of file
   fs/xfs/xfs_trans.c.  Caller xfs_growfs_data+0x691/0xe90
 CPU: 0 PID: 573 Comm: xfs_growfs Not tainted 6.3.0-rc7-next-20230420-00001-gda8c95746257
 Call Trace:
  <TASK>
  dump_stack_lvl+0x50/0x70
  xfs_error_report+0x93/0xc0
  xfs_trans_cancel+0x2c0/0x350
  xfs_growfs_data+0x691/0xe90
  xfs_file_ioctl+0x5f9/0x14a0
  __x64_sys_ioctl+0x13e/0x1c0
  do_syscall_64+0x39/0x80
  entry_SYSCALL_64_after_hwframe+0x63/0xcd
 RIP: 0033:0x7f2d86706577

The bug can be reproduced with the following sequence:

 # truncate -s  1073741824 xfs_test.img
 # mkfs.xfs -f -b size=1024 -d agcount=4 xfs_test.img
 # truncate -s 2305843009213693952  xfs_test.img
 # mount -o loop xfs_test.img /mnt/test
 # xfs_growfs -D  1125899907891200  /mnt/test

The root cause is that during growfs, user space passed in a large value
of newblcoks to xfs_growfs_data_private(), due to current sb_agblocks is
too small, new AG count will exceed UINT_MAX. Because of AG number type
is unsigned int and it would overflow, that caused nagcount much smaller
than the actual value. During AG extent space, delta blocks in
xfs_resizefs_init_new_ags() will much larger than the actual value due to
incorrect nagcount, even exceed UINT_MAX. This will cause corruption and
be detected in __xfs_free_extent. Fix it by growing the filesystem to up
to the maximally allowed AGs when new AG count overflow.

Signed-off-by: Long Li <leo.lilong@huawei.com>
---
v3:
- Ensure that the performance is consisent before and after the modification
  when nagcount just overflows and 0 < nb_mod < XFS_MIN_AG_BLOCKS. 
- Based on Darrick's advice, growing the filesystem to up to the maximally
  allowed AGs when new AG count overflow.

 fs/xfs/libxfs/xfs_fs.h |  3 +++
 fs/xfs/xfs_fsops.c     | 13 +++++++++----
 2 files changed, 12 insertions(+), 4 deletions(-)

Comments

Darrick J. Wong May 24, 2023, 2:48 p.m. UTC | #1
On Wed, May 24, 2023 at 08:10:41PM +0800, Long Li wrote:
> I found a corruption during growfs:
> 
>  XFS (loop0): Internal error agbno >= mp->m_sb.sb_agblocks at line 3661 of
>    file fs/xfs/libxfs/xfs_alloc.c.  Caller __xfs_free_extent+0x28e/0x3c0
>  CPU: 0 PID: 573 Comm: xfs_growfs Not tainted 6.3.0-rc7-next-20230420-00001-gda8c95746257
>  Call Trace:
>   <TASK>
>   dump_stack_lvl+0x50/0x70
>   xfs_corruption_error+0x134/0x150
>   __xfs_free_extent+0x2c1/0x3c0
>   xfs_ag_extend_space+0x291/0x3e0
>   xfs_growfs_data+0xd72/0xe90
>   xfs_file_ioctl+0x5f9/0x14a0
>   __x64_sys_ioctl+0x13e/0x1c0
>   do_syscall_64+0x39/0x80
>   entry_SYSCALL_64_after_hwframe+0x63/0xcd
>  XFS (loop0): Corruption detected. Unmount and run xfs_repair
>  XFS (loop0): Internal error xfs_trans_cancel at line 1097 of file
>    fs/xfs/xfs_trans.c.  Caller xfs_growfs_data+0x691/0xe90
>  CPU: 0 PID: 573 Comm: xfs_growfs Not tainted 6.3.0-rc7-next-20230420-00001-gda8c95746257
>  Call Trace:
>   <TASK>
>   dump_stack_lvl+0x50/0x70
>   xfs_error_report+0x93/0xc0
>   xfs_trans_cancel+0x2c0/0x350
>   xfs_growfs_data+0x691/0xe90
>   xfs_file_ioctl+0x5f9/0x14a0
>   __x64_sys_ioctl+0x13e/0x1c0
>   do_syscall_64+0x39/0x80
>   entry_SYSCALL_64_after_hwframe+0x63/0xcd
>  RIP: 0033:0x7f2d86706577
> 
> The bug can be reproduced with the following sequence:
> 
>  # truncate -s  1073741824 xfs_test.img
>  # mkfs.xfs -f -b size=1024 -d agcount=4 xfs_test.img
>  # truncate -s 2305843009213693952  xfs_test.img
>  # mount -o loop xfs_test.img /mnt/test
>  # xfs_growfs -D  1125899907891200  /mnt/test
> 
> The root cause is that during growfs, user space passed in a large value
> of newblcoks to xfs_growfs_data_private(), due to current sb_agblocks is
> too small, new AG count will exceed UINT_MAX. Because of AG number type
> is unsigned int and it would overflow, that caused nagcount much smaller
> than the actual value. During AG extent space, delta blocks in
> xfs_resizefs_init_new_ags() will much larger than the actual value due to
> incorrect nagcount, even exceed UINT_MAX. This will cause corruption and
> be detected in __xfs_free_extent. Fix it by growing the filesystem to up
> to the maximally allowed AGs when new AG count overflow.
> 
> Signed-off-by: Long Li <leo.lilong@huawei.com>
> ---
> v3:
> - Ensure that the performance is consisent before and after the modification
>   when nagcount just overflows and 0 < nb_mod < XFS_MIN_AG_BLOCKS. 
> - Based on Darrick's advice, growing the filesystem to up to the maximally
>   allowed AGs when new AG count overflow.
> 
>  fs/xfs/libxfs/xfs_fs.h |  3 +++
>  fs/xfs/xfs_fsops.c     | 13 +++++++++----
>  2 files changed, 12 insertions(+), 4 deletions(-)
> 
> diff --git a/fs/xfs/libxfs/xfs_fs.h b/fs/xfs/libxfs/xfs_fs.h
> index 1cfd5bc6520a..36ec2b1f7e68 100644
> --- a/fs/xfs/libxfs/xfs_fs.h
> +++ b/fs/xfs/libxfs/xfs_fs.h
> @@ -248,6 +248,9 @@ typedef struct xfs_fsop_resblks {
>  #define XFS_MAX_LOG_BLOCKS	(1024 * 1024ULL)
>  #define XFS_MIN_LOG_BYTES	(10 * 1024 * 1024ULL)
>  
> +/* Maximum number of AGs */
> +#define XFS_AGNUMBER_MAX	((xfs_agnumber_t)(-1U))

My apologies, I led you astray.  This should be:

#define XFS_MAX_AGNUMBER	((xfs_agnumber_t)(NULLAGNUMBER - 1))

since it already exists in multidisk.h from xfsprogs.
xfs_validate_sb_common probably ought to validate that
sb_agcount <= XFS_MAX_AGNUMBER as well.

> +
>  /*
>   * Limits on sb_agblocks/sb_agblklog -- mkfs won't format AGs smaller than
>   * 16MB or larger than 1TB.
> diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c
> index 13851c0d640b..2b37d3e61bdf 100644
> --- a/fs/xfs/xfs_fsops.c
> +++ b/fs/xfs/xfs_fsops.c
> @@ -115,11 +115,16 @@ xfs_growfs_data_private(
>  
>  	nb_div = nb;
>  	nb_mod = do_div(nb_div, mp->m_sb.sb_agblocks);
> -	nagcount = nb_div + (nb_mod != 0);
> -	if (nb_mod && nb_mod < XFS_MIN_AG_BLOCKS) {
> -		nagcount--;
> -		nb = (xfs_rfsblock_t)nagcount * mp->m_sb.sb_agblocks;
> +	if (nb_mod && nb_mod >= XFS_MIN_AG_BLOCKS)
> +		nb_div++;
> +	else if (nb_mod)
> +		nb = nb_div * mp->m_sb.sb_agblocks;
> +
> +	if (nb_div > XFS_AGNUMBER_MAX) {
> +		nb_div = XFS_AGNUMBER_MAX;
> +		nb = nb_div * mp->m_sb.sb_agblocks;
>  	}
> +	nagcount = nb_div;
>  	delta = nb - mp->m_sb.sb_dblocks;
>  	/*
>  	 * Reject filesystems with a single AG because they are not
> -- 
> 2.31.1
>
Long Li May 25, 2023, 7:57 a.m. UTC | #2
On Wed, May 24, 2023 at 07:48:00AM -0700, Darrick J. Wong wrote:
> On Wed, May 24, 2023 at 08:10:41PM +0800, Long Li wrote:
> > I found a corruption during growfs:
> > 
> >  XFS (loop0): Internal error agbno >= mp->m_sb.sb_agblocks at line 3661 of
> >    file fs/xfs/libxfs/xfs_alloc.c.  Caller __xfs_free_extent+0x28e/0x3c0
> >  CPU: 0 PID: 573 Comm: xfs_growfs Not tainted 6.3.0-rc7-next-20230420-00001-gda8c95746257
> >  Call Trace:
> >   <TASK>
> >   dump_stack_lvl+0x50/0x70
> >   xfs_corruption_error+0x134/0x150
> >   __xfs_free_extent+0x2c1/0x3c0
> >   xfs_ag_extend_space+0x291/0x3e0
> >   xfs_growfs_data+0xd72/0xe90
> >   xfs_file_ioctl+0x5f9/0x14a0
> >   __x64_sys_ioctl+0x13e/0x1c0
> >   do_syscall_64+0x39/0x80
> >   entry_SYSCALL_64_after_hwframe+0x63/0xcd
> >  XFS (loop0): Corruption detected. Unmount and run xfs_repair
> >  XFS (loop0): Internal error xfs_trans_cancel at line 1097 of file
> >    fs/xfs/xfs_trans.c.  Caller xfs_growfs_data+0x691/0xe90
> >  CPU: 0 PID: 573 Comm: xfs_growfs Not tainted 6.3.0-rc7-next-20230420-00001-gda8c95746257
> >  Call Trace:
> >   <TASK>
> >   dump_stack_lvl+0x50/0x70
> >   xfs_error_report+0x93/0xc0
> >   xfs_trans_cancel+0x2c0/0x350
> >   xfs_growfs_data+0x691/0xe90
> >   xfs_file_ioctl+0x5f9/0x14a0
> >   __x64_sys_ioctl+0x13e/0x1c0
> >   do_syscall_64+0x39/0x80
> >   entry_SYSCALL_64_after_hwframe+0x63/0xcd
> >  RIP: 0033:0x7f2d86706577
> > 
> > The bug can be reproduced with the following sequence:
> > 
> >  # truncate -s  1073741824 xfs_test.img
> >  # mkfs.xfs -f -b size=1024 -d agcount=4 xfs_test.img
> >  # truncate -s 2305843009213693952  xfs_test.img
> >  # mount -o loop xfs_test.img /mnt/test
> >  # xfs_growfs -D  1125899907891200  /mnt/test
> > 
> > The root cause is that during growfs, user space passed in a large value
> > of newblcoks to xfs_growfs_data_private(), due to current sb_agblocks is
> > too small, new AG count will exceed UINT_MAX. Because of AG number type
> > is unsigned int and it would overflow, that caused nagcount much smaller
> > than the actual value. During AG extent space, delta blocks in
> > xfs_resizefs_init_new_ags() will much larger than the actual value due to
> > incorrect nagcount, even exceed UINT_MAX. This will cause corruption and
> > be detected in __xfs_free_extent. Fix it by growing the filesystem to up
> > to the maximally allowed AGs when new AG count overflow.
> > 
> > Signed-off-by: Long Li <leo.lilong@huawei.com>
> > ---
> > v3:
> > - Ensure that the performance is consisent before and after the modification
> >   when nagcount just overflows and 0 < nb_mod < XFS_MIN_AG_BLOCKS. 
> > - Based on Darrick's advice, growing the filesystem to up to the maximally
> >   allowed AGs when new AG count overflow.
> > 
> >  fs/xfs/libxfs/xfs_fs.h |  3 +++
> >  fs/xfs/xfs_fsops.c     | 13 +++++++++----
> >  2 files changed, 12 insertions(+), 4 deletions(-)
> > 
> > diff --git a/fs/xfs/libxfs/xfs_fs.h b/fs/xfs/libxfs/xfs_fs.h
> > index 1cfd5bc6520a..36ec2b1f7e68 100644
> > --- a/fs/xfs/libxfs/xfs_fs.h
> > +++ b/fs/xfs/libxfs/xfs_fs.h
> > @@ -248,6 +248,9 @@ typedef struct xfs_fsop_resblks {
> >  #define XFS_MAX_LOG_BLOCKS	(1024 * 1024ULL)
> >  #define XFS_MIN_LOG_BYTES	(10 * 1024 * 1024ULL)
> >  
> > +/* Maximum number of AGs */
> > +#define XFS_AGNUMBER_MAX	((xfs_agnumber_t)(-1U))
> 
> My apologies, I led you astray.  This should be:
> 
> #define XFS_MAX_AGNUMBER	((xfs_agnumber_t)(NULLAGNUMBER - 1))
> 
OK, it is undoubtedly better to follow the definition in xfsprogs, which will
be modified in the next version.

> since it already exists in multidisk.h from xfsprogs.
> xfs_validate_sb_common probably ought to validate that
> sb_agcount <= XFS_MAX_AGNUMBER as well.
> 
In my understanding the range of sb_agcount should be [1, 0xFFFFFFFF], it
should validate that sb_agcount <= (XFS_MAX_AGNUMBER + 1) , so it's not necessary
to check the upper limit of the sb_agcount.

> > +
> >  /*
> >   * Limits on sb_agblocks/sb_agblklog -- mkfs won't format AGs smaller than
> >   * 16MB or larger than 1TB.
> > diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c
> > index 13851c0d640b..2b37d3e61bdf 100644
> > --- a/fs/xfs/xfs_fsops.c
> > +++ b/fs/xfs/xfs_fsops.c
> > @@ -115,11 +115,16 @@ xfs_growfs_data_private(
> >  
> >  	nb_div = nb;
> >  	nb_mod = do_div(nb_div, mp->m_sb.sb_agblocks);
> > -	nagcount = nb_div + (nb_mod != 0);
> > -	if (nb_mod && nb_mod < XFS_MIN_AG_BLOCKS) {
> > -		nagcount--;
> > -		nb = (xfs_rfsblock_t)nagcount * mp->m_sb.sb_agblocks;
> > +	if (nb_mod && nb_mod >= XFS_MIN_AG_BLOCKS)
> > +		nb_div++;
> > +	else if (nb_mod)
> > +		nb = nb_div * mp->m_sb.sb_agblocks;
> > +
> > +	if (nb_div > XFS_AGNUMBER_MAX) {
> > +		nb_div = XFS_AGNUMBER_MAX;
> > +		nb = nb_div * mp->m_sb.sb_agblocks;
> >  	}
> > +	nagcount = nb_div;
> >  	delta = nb - mp->m_sb.sb_dblocks;
> >  	/*
> >  	 * Reject filesystems with a single AG because they are not
> > -- 
> > 2.31.1
> >
Long Li June 1, 2023, 7:55 a.m. UTC | #3
Hi, Darrick

I realized there may be a problem with my email so you may not receive my
previous reply. So I'm replying to you with another email address, and if
you received my previous reply, you can ignore this email. Thank you very much!

On Wed, May 24, 2023 at 07:48:00AM -0700, Darrick J. Wong wrote:
> On Wed, May 24, 2023 at 08:10:41PM +0800, Long Li wrote:
> > I found a corruption during growfs:
> > 
> >  XFS (loop0): Internal error agbno >= mp->m_sb.sb_agblocks at line 3661 of
> >    file fs/xfs/libxfs/xfs_alloc.c.  Caller __xfs_free_extent+0x28e/0x3c0
> >  CPU: 0 PID: 573 Comm: xfs_growfs Not tainted 6.3.0-rc7-next-20230420-00001-gda8c95746257
> >  Call Trace:
> >   <TASK>
> >   dump_stack_lvl+0x50/0x70
> >   xfs_corruption_error+0x134/0x150
> >   __xfs_free_extent+0x2c1/0x3c0
> >   xfs_ag_extend_space+0x291/0x3e0
> >   xfs_growfs_data+0xd72/0xe90
> >   xfs_file_ioctl+0x5f9/0x14a0
> >   __x64_sys_ioctl+0x13e/0x1c0
> >   do_syscall_64+0x39/0x80
> >   entry_SYSCALL_64_after_hwframe+0x63/0xcd
> >  XFS (loop0): Corruption detected. Unmount and run xfs_repair
> >  XFS (loop0): Internal error xfs_trans_cancel at line 1097 of file
> >    fs/xfs/xfs_trans.c.  Caller xfs_growfs_data+0x691/0xe90
> >  CPU: 0 PID: 573 Comm: xfs_growfs Not tainted 6.3.0-rc7-next-20230420-00001-gda8c95746257
> >  Call Trace:
> >   <TASK>
> >   dump_stack_lvl+0x50/0x70
> >   xfs_error_report+0x93/0xc0
> >   xfs_trans_cancel+0x2c0/0x350
> >   xfs_growfs_data+0x691/0xe90
> >   xfs_file_ioctl+0x5f9/0x14a0
> >   __x64_sys_ioctl+0x13e/0x1c0
> >   do_syscall_64+0x39/0x80
> >   entry_SYSCALL_64_after_hwframe+0x63/0xcd
> >  RIP: 0033:0x7f2d86706577
> > 
> > The bug can be reproduced with the following sequence:
> > 
> >  # truncate -s  1073741824 xfs_test.img
> >  # mkfs.xfs -f -b size=1024 -d agcount=4 xfs_test.img
> >  # truncate -s 2305843009213693952  xfs_test.img
> >  # mount -o loop xfs_test.img /mnt/test
> >  # xfs_growfs -D  1125899907891200  /mnt/test
> > 
> > The root cause is that during growfs, user space passed in a large value
> > of newblcoks to xfs_growfs_data_private(), due to current sb_agblocks is
> > too small, new AG count will exceed UINT_MAX. Because of AG number type
> > is unsigned int and it would overflow, that caused nagcount much smaller
> > than the actual value. During AG extent space, delta blocks in
> > xfs_resizefs_init_new_ags() will much larger than the actual value due to
> > incorrect nagcount, even exceed UINT_MAX. This will cause corruption and
> > be detected in __xfs_free_extent. Fix it by growing the filesystem to up
> > to the maximally allowed AGs when new AG count overflow.
> > 
> > Signed-off-by: Long Li <leo.lilong@huawei.com>
> > ---
> > v3:
> > - Ensure that the performance is consisent before and after the modification
> >   when nagcount just overflows and 0 < nb_mod < XFS_MIN_AG_BLOCKS. 
> > - Based on Darrick's advice, growing the filesystem to up to the maximally
> >   allowed AGs when new AG count overflow.
> > 
> >  fs/xfs/libxfs/xfs_fs.h |  3 +++
> >  fs/xfs/xfs_fsops.c     | 13 +++++++++----
> >  2 files changed, 12 insertions(+), 4 deletions(-)
> > 
> > diff --git a/fs/xfs/libxfs/xfs_fs.h b/fs/xfs/libxfs/xfs_fs.h
> > index 1cfd5bc6520a..36ec2b1f7e68 100644
> > --- a/fs/xfs/libxfs/xfs_fs.h
> > +++ b/fs/xfs/libxfs/xfs_fs.h
> > @@ -248,6 +248,9 @@ typedef struct xfs_fsop_resblks {
> >  #define XFS_MAX_LOG_BLOCKS	(1024 * 1024ULL)
> >  #define XFS_MIN_LOG_BYTES	(10 * 1024 * 1024ULL)
> >  
> > +/* Maximum number of AGs */
> > +#define XFS_AGNUMBER_MAX	((xfs_agnumber_t)(-1U))
> 
> My apologies, I led you astray.  This should be:
> 
> #define XFS_MAX_AGNUMBER	((xfs_agnumber_t)(NULLAGNUMBER - 1))

OK, it is undoubtedly better to follow the definition in xfsprogs, which will
be modified in the next version.

> 
> since it already exists in multidisk.h from xfsprogs.
> xfs_validate_sb_common probably ought to validate that
> sb_agcount <= XFS_MAX_AGNUMBER as well.

In my understanding the range of sb_agcount should be [1, 0xFFFFFFFF], it
should validate that sb_agcount <= (XFS_MAX_AGNUMBER + 1) , so it's not necessary
to check the upper limit of the sb_agcount.

Thanks,
Long Li

> 
> > +
> >  /*
> >   * Limits on sb_agblocks/sb_agblklog -- mkfs won't format AGs smaller than
> >   * 16MB or larger than 1TB.
> > diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c
> > index 13851c0d640b..2b37d3e61bdf 100644
> > --- a/fs/xfs/xfs_fsops.c
> > +++ b/fs/xfs/xfs_fsops.c
> > @@ -115,11 +115,16 @@ xfs_growfs_data_private(
> >  
> >  	nb_div = nb;
> >  	nb_mod = do_div(nb_div, mp->m_sb.sb_agblocks);
> > -	nagcount = nb_div + (nb_mod != 0);
> > -	if (nb_mod && nb_mod < XFS_MIN_AG_BLOCKS) {
> > -		nagcount--;
> > -		nb = (xfs_rfsblock_t)nagcount * mp->m_sb.sb_agblocks;
> > +	if (nb_mod && nb_mod >= XFS_MIN_AG_BLOCKS)
> > +		nb_div++;
> > +	else if (nb_mod)
> > +		nb = nb_div * mp->m_sb.sb_agblocks;
> > +
> > +	if (nb_div > XFS_AGNUMBER_MAX) {
> > +		nb_div = XFS_AGNUMBER_MAX;
> > +		nb = nb_div * mp->m_sb.sb_agblocks;
> >  	}
> > +	nagcount = nb_div;
> >  	delta = nb - mp->m_sb.sb_dblocks;
> >  	/*
> >  	 * Reject filesystems with a single AG because they are not
> > -- 
> > 2.31.1
> >
Darrick J. Wong June 1, 2023, 2:47 p.m. UTC | #4
On Thu, Jun 01, 2023 at 03:55:53PM +0800, Long Li wrote:
> Hi, Darrick
> 
> I realized there may be a problem with my email so you may not receive my
> previous reply. So I'm replying to you with another email address, and if
> you received my previous reply, you can ignore this email. Thank you very much!

Oh, I saw it, but I've been on vacation for a week and hadn't responded
to it (or much anything else) ...

> On Wed, May 24, 2023 at 07:48:00AM -0700, Darrick J. Wong wrote:
> > On Wed, May 24, 2023 at 08:10:41PM +0800, Long Li wrote:
> > > I found a corruption during growfs:
> > > 
> > >  XFS (loop0): Internal error agbno >= mp->m_sb.sb_agblocks at line 3661 of
> > >    file fs/xfs/libxfs/xfs_alloc.c.  Caller __xfs_free_extent+0x28e/0x3c0
> > >  CPU: 0 PID: 573 Comm: xfs_growfs Not tainted 6.3.0-rc7-next-20230420-00001-gda8c95746257
> > >  Call Trace:
> > >   <TASK>
> > >   dump_stack_lvl+0x50/0x70
> > >   xfs_corruption_error+0x134/0x150
> > >   __xfs_free_extent+0x2c1/0x3c0
> > >   xfs_ag_extend_space+0x291/0x3e0
> > >   xfs_growfs_data+0xd72/0xe90
> > >   xfs_file_ioctl+0x5f9/0x14a0
> > >   __x64_sys_ioctl+0x13e/0x1c0
> > >   do_syscall_64+0x39/0x80
> > >   entry_SYSCALL_64_after_hwframe+0x63/0xcd
> > >  XFS (loop0): Corruption detected. Unmount and run xfs_repair
> > >  XFS (loop0): Internal error xfs_trans_cancel at line 1097 of file
> > >    fs/xfs/xfs_trans.c.  Caller xfs_growfs_data+0x691/0xe90
> > >  CPU: 0 PID: 573 Comm: xfs_growfs Not tainted 6.3.0-rc7-next-20230420-00001-gda8c95746257
> > >  Call Trace:
> > >   <TASK>
> > >   dump_stack_lvl+0x50/0x70
> > >   xfs_error_report+0x93/0xc0
> > >   xfs_trans_cancel+0x2c0/0x350
> > >   xfs_growfs_data+0x691/0xe90
> > >   xfs_file_ioctl+0x5f9/0x14a0
> > >   __x64_sys_ioctl+0x13e/0x1c0
> > >   do_syscall_64+0x39/0x80
> > >   entry_SYSCALL_64_after_hwframe+0x63/0xcd
> > >  RIP: 0033:0x7f2d86706577
> > > 
> > > The bug can be reproduced with the following sequence:
> > > 
> > >  # truncate -s  1073741824 xfs_test.img
> > >  # mkfs.xfs -f -b size=1024 -d agcount=4 xfs_test.img
> > >  # truncate -s 2305843009213693952  xfs_test.img
> > >  # mount -o loop xfs_test.img /mnt/test
> > >  # xfs_growfs -D  1125899907891200  /mnt/test
> > > 
> > > The root cause is that during growfs, user space passed in a large value
> > > of newblcoks to xfs_growfs_data_private(), due to current sb_agblocks is
> > > too small, new AG count will exceed UINT_MAX. Because of AG number type
> > > is unsigned int and it would overflow, that caused nagcount much smaller
> > > than the actual value. During AG extent space, delta blocks in
> > > xfs_resizefs_init_new_ags() will much larger than the actual value due to
> > > incorrect nagcount, even exceed UINT_MAX. This will cause corruption and
> > > be detected in __xfs_free_extent. Fix it by growing the filesystem to up
> > > to the maximally allowed AGs when new AG count overflow.
> > > 
> > > Signed-off-by: Long Li <leo.lilong@huawei.com>
> > > ---
> > > v3:
> > > - Ensure that the performance is consisent before and after the modification
> > >   when nagcount just overflows and 0 < nb_mod < XFS_MIN_AG_BLOCKS. 
> > > - Based on Darrick's advice, growing the filesystem to up to the maximally
> > >   allowed AGs when new AG count overflow.
> > > 
> > >  fs/xfs/libxfs/xfs_fs.h |  3 +++
> > >  fs/xfs/xfs_fsops.c     | 13 +++++++++----
> > >  2 files changed, 12 insertions(+), 4 deletions(-)
> > > 
> > > diff --git a/fs/xfs/libxfs/xfs_fs.h b/fs/xfs/libxfs/xfs_fs.h
> > > index 1cfd5bc6520a..36ec2b1f7e68 100644
> > > --- a/fs/xfs/libxfs/xfs_fs.h
> > > +++ b/fs/xfs/libxfs/xfs_fs.h
> > > @@ -248,6 +248,9 @@ typedef struct xfs_fsop_resblks {
> > >  #define XFS_MAX_LOG_BLOCKS	(1024 * 1024ULL)
> > >  #define XFS_MIN_LOG_BYTES	(10 * 1024 * 1024ULL)
> > >  
> > > +/* Maximum number of AGs */
> > > +#define XFS_AGNUMBER_MAX	((xfs_agnumber_t)(-1U))
> > 
> > My apologies, I led you astray.  This should be:
> > 
> > #define XFS_MAX_AGNUMBER	((xfs_agnumber_t)(NULLAGNUMBER - 1))
> 
> OK, it is undoubtedly better to follow the definition in xfsprogs, which will
> be modified in the next version.
> 
> > 
> > since it already exists in multidisk.h from xfsprogs.
> > xfs_validate_sb_common probably ought to validate that
> > sb_agcount <= XFS_MAX_AGNUMBER as well.
> 
> In my understanding the range of sb_agcount should be [1, 0xFFFFFFFF], it
> should validate that sb_agcount <= (XFS_MAX_AGNUMBER + 1) , so it's not necessary
> to check the upper limit of the sb_agcount.

Yes, you're correct, no new validation is needed.

--D

> 
> Thanks,
> Long Li
> 
> > 
> > > +
> > >  /*
> > >   * Limits on sb_agblocks/sb_agblklog -- mkfs won't format AGs smaller than
> > >   * 16MB or larger than 1TB.
> > > diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c
> > > index 13851c0d640b..2b37d3e61bdf 100644
> > > --- a/fs/xfs/xfs_fsops.c
> > > +++ b/fs/xfs/xfs_fsops.c
> > > @@ -115,11 +115,16 @@ xfs_growfs_data_private(
> > >  
> > >  	nb_div = nb;
> > >  	nb_mod = do_div(nb_div, mp->m_sb.sb_agblocks);
> > > -	nagcount = nb_div + (nb_mod != 0);
> > > -	if (nb_mod && nb_mod < XFS_MIN_AG_BLOCKS) {
> > > -		nagcount--;
> > > -		nb = (xfs_rfsblock_t)nagcount * mp->m_sb.sb_agblocks;
> > > +	if (nb_mod && nb_mod >= XFS_MIN_AG_BLOCKS)
> > > +		nb_div++;
> > > +	else if (nb_mod)
> > > +		nb = nb_div * mp->m_sb.sb_agblocks;
> > > +
> > > +	if (nb_div > XFS_AGNUMBER_MAX) {
> > > +		nb_div = XFS_AGNUMBER_MAX;
> > > +		nb = nb_div * mp->m_sb.sb_agblocks;
> > >  	}
> > > +	nagcount = nb_div;
> > >  	delta = nb - mp->m_sb.sb_dblocks;
> > >  	/*
> > >  	 * Reject filesystems with a single AG because they are not
> > > -- 
> > > 2.31.1
> > > 
>
diff mbox series

Patch

diff --git a/fs/xfs/libxfs/xfs_fs.h b/fs/xfs/libxfs/xfs_fs.h
index 1cfd5bc6520a..36ec2b1f7e68 100644
--- a/fs/xfs/libxfs/xfs_fs.h
+++ b/fs/xfs/libxfs/xfs_fs.h
@@ -248,6 +248,9 @@  typedef struct xfs_fsop_resblks {
 #define XFS_MAX_LOG_BLOCKS	(1024 * 1024ULL)
 #define XFS_MIN_LOG_BYTES	(10 * 1024 * 1024ULL)
 
+/* Maximum number of AGs */
+#define XFS_AGNUMBER_MAX	((xfs_agnumber_t)(-1U))
+
 /*
  * Limits on sb_agblocks/sb_agblklog -- mkfs won't format AGs smaller than
  * 16MB or larger than 1TB.
diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c
index 13851c0d640b..2b37d3e61bdf 100644
--- a/fs/xfs/xfs_fsops.c
+++ b/fs/xfs/xfs_fsops.c
@@ -115,11 +115,16 @@  xfs_growfs_data_private(
 
 	nb_div = nb;
 	nb_mod = do_div(nb_div, mp->m_sb.sb_agblocks);
-	nagcount = nb_div + (nb_mod != 0);
-	if (nb_mod && nb_mod < XFS_MIN_AG_BLOCKS) {
-		nagcount--;
-		nb = (xfs_rfsblock_t)nagcount * mp->m_sb.sb_agblocks;
+	if (nb_mod && nb_mod >= XFS_MIN_AG_BLOCKS)
+		nb_div++;
+	else if (nb_mod)
+		nb = nb_div * mp->m_sb.sb_agblocks;
+
+	if (nb_div > XFS_AGNUMBER_MAX) {
+		nb_div = XFS_AGNUMBER_MAX;
+		nb = nb_div * mp->m_sb.sb_agblocks;
 	}
+	nagcount = nb_div;
 	delta = nb - mp->m_sb.sb_dblocks;
 	/*
 	 * Reject filesystems with a single AG because they are not