Re: [PATCH V4 6/8] fs/ext4: Make DAX mount option a tri-state
On 2020/5/28 17:41, Jan Kara wrote: On Thu 28-05-20 16:56:51, Xiao Yang wrote: On 2020/5/28 7:50, Ira Weiny wrote: On Wed, May 27, 2020 at 01:54:54PM +0800, Xiao Yang wrote: On 2020/5/22 3:13, ira.we...@intel.com wrote: From: Ira Weiny We add 'always', 'never', and 'inode' (default). '-o dax' continues to operate the same which is equivalent to 'always'. This new functionality is limited to ext4 only. Specifically we introduce a 2nd DAX mount flag EXT4_MOUNT2_DAX_NEVER and set it and EXT4_MOUNT_DAX_ALWAYS appropriately for the mode. We also force EXT4_MOUNT2_DAX_NEVER if !CONFIG_FS_DAX. Finally, EXT4_MOUNT2_DAX_INODE is used solely to detect if the user specified that option for printing. Hi Ira, I have two questions when reviewing this patch: 1) After doing mount with the same dax=inode option, ext4/xfs shows differnt output(i.e. xfs doesn't print 'dax=inode'): --- # mount -o dax=inode /dev/pmem0 /mnt/xfstests/test/ # mount | grep pmem0 /dev/pmem0 on /mnt/xfstests/test type ext4 (rw,relatime,seclabel,dax=inode) # mount -odax=inode /dev/pmem1 /mnt/xfstests/scratch/ # mount | grep pmem1 /dev/pmem1 on /mnt/xfstests/scratch type xfs (rw,relatime,seclabel,attr2,inode64,logbufs=8,logbsize=32k,noquota) Is this expected output? why don't unify the output? Correct. dax=inode is the default. xfs treats that default the same whether you specify it on the command line or not. For ext4 Jan specifically asked that if the user specified dax=inode on the command line that it be printed on the mount options. If you don't specify anything then dax=inode is in effect but ext4 will not print anything. I had the behavior the same as XFS originally but Jan wanted it this way. The XFS behavior is IMO better and is what the new mount infrastructure gives by default. Could we unify the output? It is strange for me to use differnt output on ext4 and xfs. If we'd unify the output with XFS, it would be inconsistent with all the other ext4 mount options. So I disagree with that. I agree it is not ideal to have different behavior between xfs and ext4 but such is the historical behavior. If we want to change that, we need to change the handling for all the ext4 mount options. I'm open for that discussion but it is a problem unrelated to this patch set. Hi Jan, Thanks for your quick feedback. Of course, this doubt should not block the patch set. Best Regards, Xiao Yang Honza
Re: [PATCH V4 6/8] fs/ext4: Make DAX mount option a tri-state
On Thu 28-05-20 16:56:51, Xiao Yang wrote: > On 2020/5/28 7:50, Ira Weiny wrote: > > On Wed, May 27, 2020 at 01:54:54PM +0800, Xiao Yang wrote: > > > On 2020/5/22 3:13, ira.we...@intel.com wrote: > > > > From: Ira Weiny > > > > > > > > We add 'always', 'never', and 'inode' (default). '-o dax' continues to > > > > operate the same which is equivalent to 'always'. This new > > > > functionality is limited to ext4 only. > > > > > > > > Specifically we introduce a 2nd DAX mount flag EXT4_MOUNT2_DAX_NEVER > > > > and set > > > > it and EXT4_MOUNT_DAX_ALWAYS appropriately for the mode. > > > > > > > > We also force EXT4_MOUNT2_DAX_NEVER if !CONFIG_FS_DAX. > > > > > > > > Finally, EXT4_MOUNT2_DAX_INODE is used solely to detect if the user > > > > specified that option for printing. > > > Hi Ira, > > > > > > I have two questions when reviewing this patch: > > > 1) After doing mount with the same dax=inode option, ext4/xfs shows > > > differnt output(i.e. xfs doesn't print 'dax=inode'): > > > --- > > > # mount -o dax=inode /dev/pmem0 /mnt/xfstests/test/ > > > # mount | grep pmem0 > > > /dev/pmem0 on /mnt/xfstests/test type ext4 > > > (rw,relatime,seclabel,dax=inode) > > > > > > # mount -odax=inode /dev/pmem1 /mnt/xfstests/scratch/ > > > # mount | grep pmem1 > > > /dev/pmem1 on /mnt/xfstests/scratch type xfs > > > (rw,relatime,seclabel,attr2,inode64,logbufs=8,logbsize=32k,noquota) > > > > > > Is this expected output? why don't unify the output? > > > > Correct. dax=inode is the default. xfs treats that default the same whether > > you specify it on the command line or not. > > > > For ext4 Jan specifically asked that if the user specified dax=inode on the > > command line that it be printed on the mount options. If you don't specify > > anything then dax=inode is in effect but ext4 will not print anything. > > > > I had the behavior the same as XFS originally but Jan wanted it this way. > > The > > XFS behavior is IMO better and is what the new mount infrastructure gives by > > default. > > Could we unify the output? It is strange for me to use differnt output on > ext4 and xfs. If we'd unify the output with XFS, it would be inconsistent with all the other ext4 mount options. So I disagree with that. I agree it is not ideal to have different behavior between xfs and ext4 but such is the historical behavior. If we want to change that, we need to change the handling for all the ext4 mount options. I'm open for that discussion but it is a problem unrelated to this patch set. Honza -- Jan Kara SUSE Labs, CR
Re: [PATCH V4 6/8] fs/ext4: Make DAX mount option a tri-state
On 2020/5/28 7:50, Ira Weiny wrote:
On Wed, May 27, 2020 at 01:54:54PM +0800, Xiao Yang wrote:
On 2020/5/22 3:13, ira.we...@intel.com wrote:
From: Ira Weiny
We add 'always', 'never', and 'inode' (default). '-o dax' continues to
operate the same which is equivalent to 'always'. This new
functionality is limited to ext4 only.
Specifically we introduce a 2nd DAX mount flag EXT4_MOUNT2_DAX_NEVER and set
it and EXT4_MOUNT_DAX_ALWAYS appropriately for the mode.
We also force EXT4_MOUNT2_DAX_NEVER if !CONFIG_FS_DAX.
Finally, EXT4_MOUNT2_DAX_INODE is used solely to detect if the user
specified that option for printing.
Hi Ira,
I have two questions when reviewing this patch:
1) After doing mount with the same dax=inode option, ext4/xfs shows
differnt output(i.e. xfs doesn't print 'dax=inode'):
---
# mount -o dax=inode /dev/pmem0 /mnt/xfstests/test/
# mount | grep pmem0
/dev/pmem0 on /mnt/xfstests/test type ext4 (rw,relatime,seclabel,dax=inode)
# mount -odax=inode /dev/pmem1 /mnt/xfstests/scratch/
# mount | grep pmem1
/dev/pmem1 on /mnt/xfstests/scratch type xfs
(rw,relatime,seclabel,attr2,inode64,logbufs=8,logbsize=32k,noquota)
Is this expected output? why don't unify the output?
Correct. dax=inode is the default. xfs treats that default the same whether
you specify it on the command line or not.
For ext4 Jan specifically asked that if the user specified dax=inode on the
command line that it be printed on the mount options. If you don't specify
anything then dax=inode is in effect but ext4 will not print anything.
I had the behavior the same as XFS originally but Jan wanted it this way. The
XFS behavior is IMO better and is what the new mount infrastructure gives by
default.
Hi Ira,
Could we unify the output? It is strange for me to use differnt output
on ext4 and xfs.
2) Do mount without dax and mount with -odax=inode have the same behavior?
Yes.
---
# mount /dev/pmem0 /mnt/xfstests/test/
# mount | grep pmem0
/dev/pmem0 on /mnt/xfstests/test type ext4 (rw,relatime,seclabel)
# umount /mnt/xfstests/test
# mount -odax=inode /dev/pmem0 /mnt/xfstests/test/
# mount | grep pmem0
/dev/pmem0 on /mnt/xfstests/test type ext4 (rw,relatime,seclabel,dax=inode
---
These are the same behavior. But because you specified the option it was
echoed in the second output.
Got it, thanks for your explanation.
BTW: I focus on the support of per-file/directory DAX operations recently.
Reviewed-by: Jan Kara
Signed-off-by: Ira Weiny
---
Changes from V1:
Fix up mounting options to only show an option if specified
Fix remount to prevent dax changes
Isolate behavior to ext4 only
Changes from RFC:
Combine remount check for DAX_NEVER with DAX_ALWAYS
Update ext4_should_enable_dax()
---
fs/ext4/ext4.h | 2 ++
fs/ext4/inode.c | 2 ++
fs/ext4/super.c | 67 +
3 files changed, 61 insertions(+), 10 deletions(-)
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index f5291693ce6e..65ffb831b2b9 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1168,6 +1168,8 @@ struct ext4_inode_info {
blocks */
#define EXT4_MOUNT2_HURD_COMPAT 0x0004 /* Support
HURD-castrated
file systems */
+#define EXT4_MOUNT2_DAX_NEVER 0x0008 /* Do not allow Direct
Access */
+#define EXT4_MOUNT2_DAX_INODE 0x0010 /* For printing options only
*/
#define EXT4_MOUNT2_EXPLICIT_JOURNAL_CHECKSUM0x0008 /* User
explicitly
specified journal checksum */
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 01636cf5f322..68fac9289109 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4402,6 +4402,8 @@ static bool ext4_should_enable_dax(struct inode *inode)
{
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ if (test_opt2(inode->i_sb, DAX_NEVER))
+ return false;
if (!S_ISREG(inode->i_mode))
return false;
if (ext4_should_journal_data(inode))
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 80eb814c47eb..5e056aa20ce9 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1512,7 +1512,8 @@ enum {
Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
- Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
+ Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version,
+ Opt_dax, Opt_dax_always, Opt_dax_inode, Opt_dax_never,
Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
Re: [PATCH V4 6/8] fs/ext4: Make DAX mount option a tri-state
On Wed, May 27, 2020 at 01:54:54PM +0800, Xiao Yang wrote:
> On 2020/5/22 3:13, ira.we...@intel.com wrote:
> > From: Ira Weiny
> >
> > We add 'always', 'never', and 'inode' (default). '-o dax' continues to
> > operate the same which is equivalent to 'always'. This new
> > functionality is limited to ext4 only.
> >
> > Specifically we introduce a 2nd DAX mount flag EXT4_MOUNT2_DAX_NEVER and set
> > it and EXT4_MOUNT_DAX_ALWAYS appropriately for the mode.
> >
> > We also force EXT4_MOUNT2_DAX_NEVER if !CONFIG_FS_DAX.
> >
> > Finally, EXT4_MOUNT2_DAX_INODE is used solely to detect if the user
> > specified that option for printing.
> Hi Ira,
>
> I have two questions when reviewing this patch:
> 1) After doing mount with the same dax=inode option, ext4/xfs shows
> differnt output(i.e. xfs doesn't print 'dax=inode'):
> ---
> # mount -o dax=inode /dev/pmem0 /mnt/xfstests/test/
> # mount | grep pmem0
> /dev/pmem0 on /mnt/xfstests/test type ext4 (rw,relatime,seclabel,dax=inode)
>
> # mount -odax=inode /dev/pmem1 /mnt/xfstests/scratch/
> # mount | grep pmem1
> /dev/pmem1 on /mnt/xfstests/scratch type xfs
> (rw,relatime,seclabel,attr2,inode64,logbufs=8,logbsize=32k,noquota)
>
> Is this expected output? why don't unify the output?
Correct. dax=inode is the default. xfs treats that default the same whether
you specify it on the command line or not.
For ext4 Jan specifically asked that if the user specified dax=inode on the
command line that it be printed on the mount options. If you don't specify
anything then dax=inode is in effect but ext4 will not print anything.
I had the behavior the same as XFS originally but Jan wanted it this way. The
XFS behavior is IMO better and is what the new mount infrastructure gives by
default.
>
> 2) Do mount without dax and mount with -odax=inode have the same behavior?
Yes.
> ---
> # mount /dev/pmem0 /mnt/xfstests/test/
> # mount | grep pmem0
> /dev/pmem0 on /mnt/xfstests/test type ext4 (rw,relatime,seclabel)
> # umount /mnt/xfstests/test
> # mount -odax=inode /dev/pmem0 /mnt/xfstests/test/
> # mount | grep pmem0
> /dev/pmem0 on /mnt/xfstests/test type ext4 (rw,relatime,seclabel,dax=inode
> ---
These are the same behavior. But because you specified the option it was
echoed in the second output.
>
> BTW: I focus on the support of per-file/directory DAX operations recently.
>
> >
> > Reviewed-by: Jan Kara
> > Signed-off-by: Ira Weiny
> >
> > ---
> > Changes from V1:
> > Fix up mounting options to only show an option if specified
> > Fix remount to prevent dax changes
> > Isolate behavior to ext4 only
> >
> > Changes from RFC:
> > Combine remount check for DAX_NEVER with DAX_ALWAYS
> > Update ext4_should_enable_dax()
> > ---
> > fs/ext4/ext4.h | 2 ++
> > fs/ext4/inode.c | 2 ++
> > fs/ext4/super.c | 67 +
> > 3 files changed, 61 insertions(+), 10 deletions(-)
> >
> > diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
> > index f5291693ce6e..65ffb831b2b9 100644
> > --- a/fs/ext4/ext4.h
> > +++ b/fs/ext4/ext4.h
> > @@ -1168,6 +1168,8 @@ struct ext4_inode_info {
> > blocks */
> > #define EXT4_MOUNT2_HURD_COMPAT 0x0004 /* Support
> > HURD-castrated
> > file systems */
> > +#define EXT4_MOUNT2_DAX_NEVER 0x0008 /* Do not allow
> > Direct Access */
> > +#define EXT4_MOUNT2_DAX_INODE 0x0010 /* For printing
> > options only */
> >
> > #define EXT4_MOUNT2_EXPLICIT_JOURNAL_CHECKSUM 0x0008 /* User
> > explicitly
> > specified journal checksum */
> > diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
> > index 01636cf5f322..68fac9289109 100644
> > --- a/fs/ext4/inode.c
> > +++ b/fs/ext4/inode.c
> > @@ -4402,6 +4402,8 @@ static bool ext4_should_enable_dax(struct inode
> > *inode)
> > {
> > struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
> >
> > + if (test_opt2(inode->i_sb, DAX_NEVER))
> > + return false;
> > if (!S_ISREG(inode->i_mode))
> > return false;
> > if (ext4_should_journal_data(inode))
> > diff --git a/fs/ext4/super.c b/fs/ext4/super.c
> > index 80eb814c47eb..5e056aa20ce9 100644
> > --- a/fs/ext4/super.c
> > +++ b/fs/ext4/super.c
> > @@ -1512,7 +1512,8 @@ enum {
> > Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
> > Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
> > Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
> > - Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
> > + Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version,
> > + Opt_dax, Opt_dax_always, Opt_dax_inode, Opt_dax_never,
Re: [PATCH V4 6/8] fs/ext4: Make DAX mount option a tri-state
On 2020/5/22 3:13, ira.we...@intel.com wrote:
> From: Ira Weiny
>
> We add 'always', 'never', and 'inode' (default). '-o dax' continues to
> operate the same which is equivalent to 'always'. This new
> functionality is limited to ext4 only.
>
> Specifically we introduce a 2nd DAX mount flag EXT4_MOUNT2_DAX_NEVER and set
> it and EXT4_MOUNT_DAX_ALWAYS appropriately for the mode.
>
> We also force EXT4_MOUNT2_DAX_NEVER if !CONFIG_FS_DAX.
>
> Finally, EXT4_MOUNT2_DAX_INODE is used solely to detect if the user
> specified that option for printing.
Hi Ira,
I have two questions when reviewing this patch:
1) After doing mount with the same dax=inode option, ext4/xfs shows
differnt output(i.e. xfs doesn't print 'dax=inode'):
---
# mount -o dax=inode /dev/pmem0 /mnt/xfstests/test/
# mount | grep pmem0
/dev/pmem0 on /mnt/xfstests/test type ext4 (rw,relatime,seclabel,dax=inode)
# mount -odax=inode /dev/pmem1 /mnt/xfstests/scratch/
# mount | grep pmem1
/dev/pmem1 on /mnt/xfstests/scratch type xfs
(rw,relatime,seclabel,attr2,inode64,logbufs=8,logbsize=32k,noquota)
Is this expected output? why don't unify the output?
2) Do mount without dax and mount with -odax=inode have the same behavior?
---
# mount /dev/pmem0 /mnt/xfstests/test/
# mount | grep pmem0
/dev/pmem0 on /mnt/xfstests/test type ext4 (rw,relatime,seclabel)
# umount /mnt/xfstests/test
# mount -odax=inode /dev/pmem0 /mnt/xfstests/test/
# mount | grep pmem0
/dev/pmem0 on /mnt/xfstests/test type ext4 (rw,relatime,seclabel,dax=inode
---
BTW: I focus on the support of per-file/directory DAX operations recently.
>
> Reviewed-by: Jan Kara
> Signed-off-by: Ira Weiny
>
> ---
> Changes from V1:
> Fix up mounting options to only show an option if specified
> Fix remount to prevent dax changes
> Isolate behavior to ext4 only
>
> Changes from RFC:
> Combine remount check for DAX_NEVER with DAX_ALWAYS
> Update ext4_should_enable_dax()
> ---
> fs/ext4/ext4.h | 2 ++
> fs/ext4/inode.c | 2 ++
> fs/ext4/super.c | 67 +
> 3 files changed, 61 insertions(+), 10 deletions(-)
>
> diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
> index f5291693ce6e..65ffb831b2b9 100644
> --- a/fs/ext4/ext4.h
> +++ b/fs/ext4/ext4.h
> @@ -1168,6 +1168,8 @@ struct ext4_inode_info {
> blocks */
> #define EXT4_MOUNT2_HURD_COMPAT 0x0004 /* Support
> HURD-castrated
> file systems */
> +#define EXT4_MOUNT2_DAX_NEVER0x0008 /* Do not allow
> Direct Access */
> +#define EXT4_MOUNT2_DAX_INODE0x0010 /* For printing
> options only */
>
> #define EXT4_MOUNT2_EXPLICIT_JOURNAL_CHECKSUM 0x0008 /* User
> explicitly
> specified journal checksum */
> diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
> index 01636cf5f322..68fac9289109 100644
> --- a/fs/ext4/inode.c
> +++ b/fs/ext4/inode.c
> @@ -4402,6 +4402,8 @@ static bool ext4_should_enable_dax(struct inode *inode)
> {
> struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
>
> + if (test_opt2(inode->i_sb, DAX_NEVER))
> + return false;
> if (!S_ISREG(inode->i_mode))
> return false;
> if (ext4_should_journal_data(inode))
> diff --git a/fs/ext4/super.c b/fs/ext4/super.c
> index 80eb814c47eb..5e056aa20ce9 100644
> --- a/fs/ext4/super.c
> +++ b/fs/ext4/super.c
> @@ -1512,7 +1512,8 @@ enum {
> Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
> Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
> Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
> - Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
> + Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version,
> + Opt_dax, Opt_dax_always, Opt_dax_inode, Opt_dax_never,
> Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
> Opt_nowarn_on_error, Opt_mblk_io_submit,
> Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
> @@ -1579,6 +1580,9 @@ static const match_table_t tokens = {
> {Opt_nobarrier, "nobarrier"},
> {Opt_i_version, "i_version"},
> {Opt_dax, "dax"},
> + {Opt_dax_always, "dax=always"},
> + {Opt_dax_inode, "dax=inode"},
> + {Opt_dax_never, "dax=never"},
> {Opt_stripe, "stripe=%u"},
> {Opt_delalloc, "delalloc"},
> {Opt_warn_on_error, "warn_on_error"},
> @@ -1726,6 +1730,7 @@ static int clear_qf_name(struct super_block *sb, int
> qtype)
> #define MOPT_NO_EXT30x0200
> #define MOPT_EXT4_ONLY (MOPT_NO_EXT2 | MOPT_NO_EXT3)
> #define MOPT_STRING 0x0400
> +#define MOPT_SKIP0x0800
>
> static
[PATCH V4 6/8] fs/ext4: Make DAX mount option a tri-state
From: Ira Weiny
We add 'always', 'never', and 'inode' (default). '-o dax' continues to
operate the same which is equivalent to 'always'. This new
functionality is limited to ext4 only.
Specifically we introduce a 2nd DAX mount flag EXT4_MOUNT2_DAX_NEVER and set
it and EXT4_MOUNT_DAX_ALWAYS appropriately for the mode.
We also force EXT4_MOUNT2_DAX_NEVER if !CONFIG_FS_DAX.
Finally, EXT4_MOUNT2_DAX_INODE is used solely to detect if the user
specified that option for printing.
Reviewed-by: Jan Kara
Signed-off-by: Ira Weiny
---
Changes from V1:
Fix up mounting options to only show an option if specified
Fix remount to prevent dax changes
Isolate behavior to ext4 only
Changes from RFC:
Combine remount check for DAX_NEVER with DAX_ALWAYS
Update ext4_should_enable_dax()
---
fs/ext4/ext4.h | 2 ++
fs/ext4/inode.c | 2 ++
fs/ext4/super.c | 67 +
3 files changed, 61 insertions(+), 10 deletions(-)
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index f5291693ce6e..65ffb831b2b9 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1168,6 +1168,8 @@ struct ext4_inode_info {
blocks */
#define EXT4_MOUNT2_HURD_COMPAT0x0004 /* Support
HURD-castrated
file systems */
+#define EXT4_MOUNT2_DAX_NEVER 0x0008 /* Do not allow Direct
Access */
+#define EXT4_MOUNT2_DAX_INODE 0x0010 /* For printing options only
*/
#define EXT4_MOUNT2_EXPLICIT_JOURNAL_CHECKSUM 0x0008 /* User explicitly
specified journal checksum */
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 01636cf5f322..68fac9289109 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4402,6 +4402,8 @@ static bool ext4_should_enable_dax(struct inode *inode)
{
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ if (test_opt2(inode->i_sb, DAX_NEVER))
+ return false;
if (!S_ISREG(inode->i_mode))
return false;
if (ext4_should_journal_data(inode))
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 80eb814c47eb..5e056aa20ce9 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1512,7 +1512,8 @@ enum {
Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
- Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
+ Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version,
+ Opt_dax, Opt_dax_always, Opt_dax_inode, Opt_dax_never,
Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
Opt_nowarn_on_error, Opt_mblk_io_submit,
Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
@@ -1579,6 +1580,9 @@ static const match_table_t tokens = {
{Opt_nobarrier, "nobarrier"},
{Opt_i_version, "i_version"},
{Opt_dax, "dax"},
+ {Opt_dax_always, "dax=always"},
+ {Opt_dax_inode, "dax=inode"},
+ {Opt_dax_never, "dax=never"},
{Opt_stripe, "stripe=%u"},
{Opt_delalloc, "delalloc"},
{Opt_warn_on_error, "warn_on_error"},
@@ -1726,6 +1730,7 @@ static int clear_qf_name(struct super_block *sb, int
qtype)
#define MOPT_NO_EXT3 0x0200
#define MOPT_EXT4_ONLY (MOPT_NO_EXT2 | MOPT_NO_EXT3)
#define MOPT_STRING0x0400
+#define MOPT_SKIP 0x0800
static const struct mount_opts {
int token;
@@ -1775,7 +1780,13 @@ static const struct mount_opts {
{Opt_min_batch_time, 0, MOPT_GTE0},
{Opt_inode_readahead_blks, 0, MOPT_GTE0},
{Opt_init_itable, 0, MOPT_GTE0},
- {Opt_dax, EXT4_MOUNT_DAX_ALWAYS, MOPT_SET},
+ {Opt_dax, EXT4_MOUNT_DAX_ALWAYS, MOPT_SET | MOPT_SKIP},
+ {Opt_dax_always, EXT4_MOUNT_DAX_ALWAYS,
+ MOPT_EXT4_ONLY | MOPT_SET | MOPT_SKIP},
+ {Opt_dax_inode, EXT4_MOUNT2_DAX_INODE,
+ MOPT_EXT4_ONLY | MOPT_SET | MOPT_SKIP},
+ {Opt_dax_never, EXT4_MOUNT2_DAX_NEVER,
+ MOPT_EXT4_ONLY | MOPT_SET | MOPT_SKIP},
{Opt_stripe, 0, MOPT_GTE0},
{Opt_resuid, 0, MOPT_GTE0},
{Opt_resgid, 0, MOPT_GTE0},
@@ -2084,13 +2095,32 @@ static int handle_mount_opt(struct super_block *sb,
char *opt, int token,
}
sbi->s_jquota_fmt = m->mount_opt;
#endif
- } else if (token == Opt_dax) {
+ } else if (token == Opt_dax || token == Opt_dax_always ||
+ token == Opt_dax_inode || token == Opt_dax_never) {
#ifdef CONFIG_FS_DAX
- ext4_msg(sb, KERN_WARNING,
- "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
- sbi->s_mount_opt |= m->mount_opt;
+ switch (token) {
+ case Opt_dax:
+ case Opt_dax_always:
+
