| Message ID | 20200513054324.2138483-9-ira.weiny@intel.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [1/9] fs/ext4: Narrow scope of DAX check in setflags | expand |
On Tue 12-05-20 22:43:23, ira.weiny@intel.com wrote: > From: Ira Weiny <ira.weiny@intel.com> > > Add a flag to preserve FS_XFLAG_DAX in the ext4 inode. > > Set the flag to be user visible and changeable. Set the flag to be > inherited. Allow applications to change the flag at any time. > > Finally, on regular files, flag the inode to not be cached to facilitate > changing S_DAX on the next creation of the inode. > > Signed-off-by: Ira Weiny <ira.weiny@intel.com> > > --- > Change from RFC: > use new d_mark_dontcache() > Allow caching if ALWAYS/NEVER is set > Rebased to latest Linus master > Change flag to unused 0x01000000 > update ext4_should_enable_dax() > --- > fs/ext4/ext4.h | 13 +++++++++---- > fs/ext4/inode.c | 4 +++- > fs/ext4/ioctl.c | 25 ++++++++++++++++++++++++- > 3 files changed, 36 insertions(+), 6 deletions(-) > > diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h > index 01d1de838896..715f8f2029b2 100644 > --- a/fs/ext4/ext4.h > +++ b/fs/ext4/ext4.h > @@ -415,13 +415,16 @@ struct flex_groups { > #define EXT4_VERITY_FL 0x00100000 /* Verity protected inode */ > #define EXT4_EA_INODE_FL 0x00200000 /* Inode used for large EA */ > /* 0x00400000 was formerly EXT4_EOFBLOCKS_FL */ > + > +#define EXT4_DAX_FL 0x01000000 /* Inode is DAX */ > + > #define EXT4_INLINE_DATA_FL 0x10000000 /* Inode has inline data. */ > #define EXT4_PROJINHERIT_FL 0x20000000 /* Create with parents projid */ > #define EXT4_CASEFOLD_FL 0x40000000 /* Casefolded file */ > #define EXT4_RESERVED_FL 0x80000000 /* reserved for ext4 lib */ > > -#define EXT4_FL_USER_VISIBLE 0x705BDFFF /* User visible flags */ > -#define EXT4_FL_USER_MODIFIABLE 0x604BC0FF /* User modifiable flags */ > +#define EXT4_FL_USER_VISIBLE 0x715BDFFF /* User visible flags */ > +#define EXT4_FL_USER_MODIFIABLE 0x614BC0FF /* User modifiable flags */ Hum, I think this was already mentioned but there are also definitions in include/uapi/linux/fs.h which should be kept in sync... Also if DAX flag gets modified through FS_IOC_SETFLAGS, we should call ext4_doncache() as well, shouldn't we? > @@ -802,6 +807,21 @@ static int ext4_ioctl_get_es_cache(struct file *filp, unsigned long arg) > return error; > } > > +static void ext4_dax_dontcache(struct inode *inode, unsigned int flags) > +{ > + struct ext4_inode_info *ei = EXT4_I(inode); > + > + if (S_ISDIR(inode->i_mode)) > + return; > + > + if (test_opt2(inode->i_sb, DAX_NEVER) || > + test_opt(inode->i_sb, DAX_ALWAYS)) > + return; > + > + if (((ei->i_flags ^ flags) & EXT4_DAX_FL) == EXT4_DAX_FL) > + d_mark_dontcache(inode); > +} > + > long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) > { > struct inode *inode = file_inode(filp); > @@ -1267,6 +1287,9 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) > return err; > > inode_lock(inode); > + > + ext4_dax_dontcache(inode, flags); > + I don't think we should set dontcache flag when setting of DAX flag fails - it could event be a security issue). So I think you'll have to check whether DAX flag is being changed, call vfs_ioc_fssetxattr_check(), and only if it succeeded and DAX flags was changing call ext4_dax_dontcache(). Honza
On Wed, May 13, 2020 at 04:47:06PM +0200, Jan Kara wrote: > On Tue 12-05-20 22:43:23, ira.weiny@intel.com wrote: > > From: Ira Weiny <ira.weiny@intel.com> > > > > Add a flag to preserve FS_XFLAG_DAX in the ext4 inode. > > > > Set the flag to be user visible and changeable. Set the flag to be > > inherited. Allow applications to change the flag at any time. > > > > Finally, on regular files, flag the inode to not be cached to facilitate > > changing S_DAX on the next creation of the inode. > > > > Signed-off-by: Ira Weiny <ira.weiny@intel.com> > > > > --- > > Change from RFC: > > use new d_mark_dontcache() > > Allow caching if ALWAYS/NEVER is set > > Rebased to latest Linus master > > Change flag to unused 0x01000000 > > update ext4_should_enable_dax() > > --- > > fs/ext4/ext4.h | 13 +++++++++---- > > fs/ext4/inode.c | 4 +++- > > fs/ext4/ioctl.c | 25 ++++++++++++++++++++++++- > > 3 files changed, 36 insertions(+), 6 deletions(-) > > > > diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h > > index 01d1de838896..715f8f2029b2 100644 > > --- a/fs/ext4/ext4.h > > +++ b/fs/ext4/ext4.h > > @@ -415,13 +415,16 @@ struct flex_groups { > > #define EXT4_VERITY_FL 0x00100000 /* Verity protected inode */ > > #define EXT4_EA_INODE_FL 0x00200000 /* Inode used for large EA */ > > /* 0x00400000 was formerly EXT4_EOFBLOCKS_FL */ > > + > > +#define EXT4_DAX_FL 0x01000000 /* Inode is DAX */ > > + > > #define EXT4_INLINE_DATA_FL 0x10000000 /* Inode has inline data. */ > > #define EXT4_PROJINHERIT_FL 0x20000000 /* Create with parents projid */ > > #define EXT4_CASEFOLD_FL 0x40000000 /* Casefolded file */ > > #define EXT4_RESERVED_FL 0x80000000 /* reserved for ext4 lib */ > > > > -#define EXT4_FL_USER_VISIBLE 0x705BDFFF /* User visible flags */ > > -#define EXT4_FL_USER_MODIFIABLE 0x604BC0FF /* User modifiable flags */ > > +#define EXT4_FL_USER_VISIBLE 0x715BDFFF /* User visible flags */ > > +#define EXT4_FL_USER_MODIFIABLE 0x614BC0FF /* User modifiable flags */ > > Hum, I think this was already mentioned but there are also definitions in > include/uapi/linux/fs.h which should be kept in sync... Also if DAX flag > gets modified through FS_IOC_SETFLAGS, we should call ext4_doncache() as > well, shouldn't we? Ah yea it was mentioned. Sorry. > > > @@ -802,6 +807,21 @@ static int ext4_ioctl_get_es_cache(struct file *filp, unsigned long arg) > > return error; > > } > > > > +static void ext4_dax_dontcache(struct inode *inode, unsigned int flags) > > +{ > > + struct ext4_inode_info *ei = EXT4_I(inode); > > + > > + if (S_ISDIR(inode->i_mode)) > > + return; > > + > > + if (test_opt2(inode->i_sb, DAX_NEVER) || > > + test_opt(inode->i_sb, DAX_ALWAYS)) > > + return; > > + > > + if (((ei->i_flags ^ flags) & EXT4_DAX_FL) == EXT4_DAX_FL) > > + d_mark_dontcache(inode); > > +} > > + > > long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) > > { > > struct inode *inode = file_inode(filp); > > @@ -1267,6 +1287,9 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) > > return err; > > > > inode_lock(inode); > > + > > + ext4_dax_dontcache(inode, flags); > > + > > I don't think we should set dontcache flag when setting of DAX flag fails - > it could event be a security issue). good point. > > So I think you'll have to check > whether DAX flag is being changed, ext4_dax_dontcache() does check if the flag is being changed. > call vfs_ioc_fssetxattr_check(), and > only if it succeeded and DAX flags was changing call ext4_dax_dontcache(). Yes I think it would be better to ensure all of the ioctl succeeds prior to setting the don't cache. The logic is easier to follow. Ira > > Honza > -- > Jan Kara <jack@suse.com> > SUSE Labs, CR
On Wed 13-05-20 14:41:55, Ira Weiny wrote: > On Wed, May 13, 2020 at 04:47:06PM +0200, Jan Kara wrote: > > > > So I think you'll have to check > > whether DAX flag is being changed, > > ext4_dax_dontcache() does check if the flag is being changed. Yes, but if you call it after inode flags change, you cannot determine that just from flags and EXT4_I(inode)->i_flags. So that logic needs to change. Honza
On Thu, May 14, 2020 at 08:43:35AM +0200, Jan Kara wrote: > On Wed 13-05-20 14:41:55, Ira Weiny wrote: > > On Wed, May 13, 2020 at 04:47:06PM +0200, Jan Kara wrote: > > > > > > So I think you'll have to check > > > whether DAX flag is being changed, > > > > ext4_dax_dontcache() does check if the flag is being changed. > > Yes, but if you call it after inode flags change, you cannot determine that > just from flags and EXT4_I(inode)->i_flags. So that logic needs to change. I just caught this email... just after sending V1. I've moved where ext4_dax_dontcache() is called. I think it is ok now with the current check. LMK if I've messed it up... :-/ Ira > > Honza > > -- > Jan Kara <jack@suse.com> > SUSE Labs, CR
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 01d1de838896..715f8f2029b2 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -415,13 +415,16 @@ struct flex_groups { #define EXT4_VERITY_FL 0x00100000 /* Verity protected inode */ #define EXT4_EA_INODE_FL 0x00200000 /* Inode used for large EA */ /* 0x00400000 was formerly EXT4_EOFBLOCKS_FL */ + +#define EXT4_DAX_FL 0x01000000 /* Inode is DAX */ + #define EXT4_INLINE_DATA_FL 0x10000000 /* Inode has inline data. */ #define EXT4_PROJINHERIT_FL 0x20000000 /* Create with parents projid */ #define EXT4_CASEFOLD_FL 0x40000000 /* Casefolded file */ #define EXT4_RESERVED_FL 0x80000000 /* reserved for ext4 lib */ -#define EXT4_FL_USER_VISIBLE 0x705BDFFF /* User visible flags */ -#define EXT4_FL_USER_MODIFIABLE 0x604BC0FF /* User modifiable flags */ +#define EXT4_FL_USER_VISIBLE 0x715BDFFF /* User visible flags */ +#define EXT4_FL_USER_MODIFIABLE 0x614BC0FF /* User modifiable flags */ /* Flags we can manipulate with through EXT4_IOC_FSSETXATTR */ #define EXT4_FL_XFLAG_VISIBLE (EXT4_SYNC_FL | \ @@ -429,14 +432,16 @@ struct flex_groups { EXT4_APPEND_FL | \ EXT4_NODUMP_FL | \ EXT4_NOATIME_FL | \ - EXT4_PROJINHERIT_FL) + EXT4_PROJINHERIT_FL | \ + EXT4_DAX_FL) /* Flags that should be inherited by new inodes from their parent. */ #define EXT4_FL_INHERITED (EXT4_SECRM_FL | EXT4_UNRM_FL | EXT4_COMPR_FL |\ EXT4_SYNC_FL | EXT4_NODUMP_FL | EXT4_NOATIME_FL |\ EXT4_NOCOMPR_FL | EXT4_JOURNAL_DATA_FL |\ EXT4_NOTAIL_FL | EXT4_DIRSYNC_FL |\ - EXT4_PROJINHERIT_FL | EXT4_CASEFOLD_FL) + EXT4_PROJINHERIT_FL | EXT4_CASEFOLD_FL |\ + EXT4_DAX_FL) /* Flags that are appropriate for regular files (all but dir-specific ones). */ #define EXT4_REG_FLMASK (~(EXT4_DIRSYNC_FL | EXT4_TOPDIR_FL | EXT4_CASEFOLD_FL |\ diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 140b1930e2f4..105cf04f7940 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -4400,6 +4400,8 @@ int ext4_get_inode_loc(struct inode *inode, struct ext4_iloc *iloc) static bool ext4_should_enable_dax(struct inode *inode) { + unsigned int flags = EXT4_I(inode)->i_flags; + if (test_opt2(inode->i_sb, DAX_NEVER)) return false; if (!S_ISREG(inode->i_mode)) @@ -4418,7 +4420,7 @@ static bool ext4_should_enable_dax(struct inode *inode) if (test_opt(inode->i_sb, DAX_ALWAYS)) return true; - return false; + return flags & EXT4_DAX_FL; } void ext4_set_inode_flags(struct inode *inode, bool init) diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c index 145083e8cd1e..6996a5c3e101 100644 --- a/fs/ext4/ioctl.c +++ b/fs/ext4/ioctl.c @@ -528,12 +528,15 @@ static inline __u32 ext4_iflags_to_xflags(unsigned long iflags) xflags |= FS_XFLAG_NOATIME; if (iflags & EXT4_PROJINHERIT_FL) xflags |= FS_XFLAG_PROJINHERIT; + if (iflags & EXT4_DAX_FL) + xflags |= FS_XFLAG_DAX; return xflags; } #define EXT4_SUPPORTED_FS_XFLAGS (FS_XFLAG_SYNC | FS_XFLAG_IMMUTABLE | \ FS_XFLAG_APPEND | FS_XFLAG_NODUMP | \ - FS_XFLAG_NOATIME | FS_XFLAG_PROJINHERIT) + FS_XFLAG_NOATIME | FS_XFLAG_PROJINHERIT | \ + FS_XFLAG_DAX) /* Transfer xflags flags to internal */ static inline unsigned long ext4_xflags_to_iflags(__u32 xflags) @@ -552,6 +555,8 @@ static inline unsigned long ext4_xflags_to_iflags(__u32 xflags) iflags |= EXT4_NOATIME_FL; if (xflags & FS_XFLAG_PROJINHERIT) iflags |= EXT4_PROJINHERIT_FL; + if (xflags & FS_XFLAG_DAX) + iflags |= EXT4_DAX_FL; return iflags; } @@ -802,6 +807,21 @@ static int ext4_ioctl_get_es_cache(struct file *filp, unsigned long arg) return error; } +static void ext4_dax_dontcache(struct inode *inode, unsigned int flags) +{ + struct ext4_inode_info *ei = EXT4_I(inode); + + if (S_ISDIR(inode->i_mode)) + return; + + if (test_opt2(inode->i_sb, DAX_NEVER) || + test_opt(inode->i_sb, DAX_ALWAYS)) + return; + + if (((ei->i_flags ^ flags) & EXT4_DAX_FL) == EXT4_DAX_FL) + d_mark_dontcache(inode); +} + long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) { struct inode *inode = file_inode(filp); @@ -1267,6 +1287,9 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) return err; inode_lock(inode); + + ext4_dax_dontcache(inode, flags); + ext4_fill_fsxattr(inode, &old_fa); err = vfs_ioc_fssetxattr_check(inode, &old_fa, &fa); if (err)