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| author |   Ira Weiny <ira.weiny@intel.com> | 2020-05-28 08:00:02 -0700 |
|---|---|---|
| committer |   Theodore Ts'o <tytso@mit.edu> | 2020-05-28 22:09:47 -0400 |
| commit | b383a73f2b832491a2f9e6e8ada26aad53b5763d (patch) | |
| tree | 1631eb8ee0a22c9116196cf92d679e6e40b3f674 /include/uapi | |
| parent | fs/ext4: Remove jflag variable (diff) | |
| download | wireguard-linux-b383a73f2b832491a2f9e6e8ada26aad53b5763d.tar.xz wireguard-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 'include/uapi')
| -rw-r--r-- | include/uapi/linux/fs.h | 1 |
1 files changed, 1 insertions, 0 deletions
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 */ |