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authorIra Weiny <ira.weiny@intel.com>2020-05-28 17:00:02 +0200
committerTheodore Ts'o <tytso@mit.edu>2020-05-29 04:09:47 +0200
commitb383a73f2b832491a2f9e6e8ada26aad53b5763d (patch)
tree1631eb8ee0a22c9116196cf92d679e6e40b3f674 /fs/ext4/ioctl.c
parentfs/ext4: Remove jflag variable (diff)
downloadlinux-b383a73f2b832491a2f9e6e8ada26aad53b5763d.tar.xz
linux-b383a73f2b832491a2f9e6e8ada26aad53b5763d.zip
fs/ext4: Introduce DAX inode flag
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@intel.com> Link: https://lore.kernel.org/r/20200528150003.828793-9-ira.weiny@intel.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/ioctl.c')
-rw-r--r--fs/ext4/ioctl.c47
1 files changed, 46 insertions, 1 deletions
diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index 779631e8e849..1b520d07d371 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;
}