From: Ira Weiny <ira.weiny@xxxxxxxxx>
Add a flag ([EXT4|FS]_DAX_FL) 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 except if
it conflicts with the set of mutually exclusive flags (Currently VERITY,
ENCRYPT, JOURNAL_DATA).
Furthermore, restrict setting any of the exclusive flags if DAX is set.
While conceptually possible, we do not allow setting EXT4_DAX_FL while
at the same time clearing exclusion flags (or vice versa) for 2 reasons:
1) The DAX flag does not take effect immediately which
introduces quite a bit of complexity
2) There is no clear use case for being this flexible
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@xxxxxxxxx>
---
Changes from V4:
Fix DAX exclusive checks
Add EXT4_JOURNAL_DATA_FL to the exclusive flags
Changes from V3:
Move bit to bit25 per Andreas
Change from V2:
Add in making verity and DAX exclusive.
'Squash' in making encryption and DAX exclusive.
Add in EXT4_INODE_DAX flag definition to be compatible with
ext4_[set|test]_inode_flag() bit operations
Use ext4_[set|test]_inode_flag() bit operations to be consistent
with other code.
Change from V0:
Add FS_DAX_FL to include/uapi/linux/fs.h
to be consistent
Move ext4_dax_dontcache() to ext4_ioctl_setflags()
This ensures that it is only set when the flags are going to be
set and not if there is an error
Also this sets don't cache in the FS_IOC_SETFLAGS case
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 | 18 ++++++++++++----
fs/ext4/inode.c | 2 +-
fs/ext4/ioctl.c | 47 ++++++++++++++++++++++++++++++++++++++++-
fs/ext4/super.c | 3 +++
fs/ext4/verity.c | 2 +-
include/uapi/linux/fs.h | 1 +
6 files changed, 66 insertions(+), 7 deletions(-)
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index d80a6d830b1c..2dcee318300f 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 0x02000000 /* 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 0x725BDFFF /* User visible flags */
+#define EXT4_FL_USER_MODIFIABLE 0x624BC0FF /* 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 |\
@@ -448,6 +453,10 @@ struct flex_groups {
/* The only flags that should be swapped */
#define EXT4_FL_SHOULD_SWAP (EXT4_HUGE_FILE_FL | EXT4_EXTENTS_FL)
+/* Flags which are mutually exclusive to DAX */
+#define EXT4_DAX_MUT_EXCL (EXT4_VERITY_FL | EXT4_ENCRYPT_FL |\
+ EXT4_JOURNAL_DATA_FL)
+
/* Mask out flags that are inappropriate for the given type of inode. */
static inline __u32 ext4_mask_flags(umode_t mode, __u32 flags)
{
@@ -488,6 +497,7 @@ enum {
EXT4_INODE_VERITY = 20, /* Verity protected inode */
EXT4_INODE_EA_INODE = 21, /* Inode used for large EA */
/* 22 was formerly EXT4_INODE_EOFBLOCKS */
+ EXT4_INODE_DAX = 25, /* Inode is DAX */
EXT4_INODE_INLINE_DATA = 28, /* Data in inode. */
EXT4_INODE_PROJINHERIT = 29, /* Create with parents projid */
EXT4_INODE_RESERVED = 31, /* reserved for ext4 lib */
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 68fac9289109..778b0dbe3da6 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4419,7 +4419,7 @@ static bool ext4_should_enable_dax(struct inode *inode)
if (test_opt(inode->i_sb, DAX_ALWAYS))
return true;
- return false;
+ return ext4_test_inode_flag(inode, EXT4_INODE_DAX);
}
void ext4_set_inode_flags(struct inode *inode, bool init)
diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index e8a5cdade59f..14f6c3a138a7 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -292,6 +292,38 @@ static int ext4_ioctl_check_immutable(struct inode *inode, __u32 new_projid,
return 0;
}
+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)
+ d_mark_dontcache(inode);
+}
+
+static bool dax_compatible(struct inode *inode, unsigned int oldflags,
+ unsigned int flags)
+{
+ if (flags & EXT4_DAX_FL) {
+ if ((oldflags & EXT4_DAX_MUT_EXCL) ||
+ ext4_test_inode_state(inode,
+ EXT4_STATE_VERITY_IN_PROGRESS)) {
+ return false;
+ }
+ }
+
+ if ((flags & EXT4_DAX_MUT_EXCL) && (oldflags & EXT4_DAX_FL))
+ return false;
+
+ return true;
+}
+
static int ext4_ioctl_setflags(struct inode *inode,
unsigned int flags)
{
@@ -320,6 +352,12 @@ static int ext4_ioctl_setflags(struct inode *inode,
if (!capable(CAP_SYS_RESOURCE))
goto flags_out;
}
+
+ if (!dax_compatible(inode, oldflags, flags)) {
+ err = -EOPNOTSUPP;
+ goto flags_out;
+ }
+
if ((flags ^ oldflags) & EXT4_EXTENTS_FL)
migrate = 1;
@@ -365,6 +403,8 @@ static int ext4_ioctl_setflags(struct inode *inode,
if (err)
goto flags_err;
+ ext4_dax_dontcache(inode, flags);
+
for (i = 0, mask = 1; i < 32; i++, mask <<= 1) {
if (!(mask & EXT4_FL_USER_MODIFIABLE))
continue;
@@ -525,12 +565,15 @@ 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)
@@ -549,6 +592,8 @@ 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;
}
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 5e056aa20ce9..3658e3016999 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1323,6 +1323,9 @@ static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
if (WARN_ON_ONCE(IS_DAX(inode) && i_size_read(inode)))
return -EINVAL;
+ if (ext4_test_inode_flag(inode, EXT4_INODE_DAX))
+ return -EOPNOTSUPP;
+
res = ext4_convert_inline_data(inode);
if (res)
return res;
diff --git a/fs/ext4/verity.c b/fs/ext4/verity.c
index 89a155ece323..4fecb3e4e338 100644
--- a/fs/ext4/verity.c
+++ b/fs/ext4/verity.c
@@ -113,7 +113,7 @@ static int ext4_begin_enable_verity(struct file *filp)
handle_t *handle;
int err;
- if (IS_DAX(inode))
+ if (IS_DAX(inode) || ext4_test_inode_flag(inode, EXT4_INODE_DAX))
return -EINVAL;
if (ext4_verity_in_progress(inode))
diff --git a/include/uapi/linux/fs.h b/include/uapi/linux/fs.h
index 379a612f8f1d..f44eb0a04afd 100644
--- a/include/uapi/linux/fs.h
+++ b/include/uapi/linux/fs.h
@@ -262,6 +262,7 @@ struct fsxattr {
#define FS_EA_INODE_FL 0x00200000 /* Inode used for large EA */
#define FS_EOFBLOCKS_FL 0x00400000 /* Reserved for ext4 */
#define FS_NOCOW_FL 0x00800000 /* Do not cow file */
+#define FS_DAX_FL 0x02000000 /* Inode is DAX */
#define FS_INLINE_DATA_FL 0x10000000 /* Reserved for ext4 */
#define FS_PROJINHERIT_FL 0x20000000 /* Create with parents projid */
#define FS_CASEFOLD_FL 0x40000000 /* Folder is case insensitive */
--
2.25.1
