Commit 68ce7bfc authored by Theodore Ts'o's avatar Theodore Ts'o

fs: clean up the flags definition in uapi/linux/fs.h

Add an explanation for the flags used by FS_IOC_[GS]ETFLAGS and remind
people that changes should be revised by linux-fsdevel and linux-api.

Add flags that are used on-disk for ext4, and remove FS_DIRECTIO_FL
since it was used only by gfs2 and support was removed in 2008 in
commit c9f6a6bb ("The ability to mark files for direct i/o access
when opened normally is both unused and pointless, so this patch
removes support for that feature.")  Now we have _two_ remaining flags
left.  But since we want to discourage people from assigning new
flags, that's OK.
Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent 9b7365fc
......@@ -2,8 +2,11 @@
#define _UAPI_LINUX_FS_H
/*
* This file has definitions for some important file table
* structures etc.
* This file has definitions for some important file table structures
* and constants and structures used by various generic file system
* ioctl's. Please do not make any changes in this file before
* sending patches for review to linux-fsdevel@vger.kernel.org and
* linux-api@vger.kernel.org.
*/
#include <linux/limits.h>
......@@ -172,6 +175,23 @@ struct inodes_stat_t {
/*
* Inode flags (FS_IOC_GETFLAGS / FS_IOC_SETFLAGS)
*
* Note: for historical reasons, these flags were originally used and
* defined for use by ext2/ext3, and then other file systems started
* using these flags so they wouldn't need to write their own version
* of chattr/lsattr (which was shipped as part of e2fsprogs). You
* should think twice before trying to use these flags in new
* contexts, or trying to assign these flags, since they are used both
* as the UAPI and the on-disk encoding for ext2/3/4. Also, we are
* almost out of 32-bit flags. :-)
*
* We have recently hoisted FS_IOC_FSGETXATTR / FS_IOC_FSSETXATTR from
* XFS to the generic FS level interface. This uses a structure that
* has padding and hence has more room to grow, so it may be more
* appropriate for many new use cases.
*
* Please do not change these flags or interfaces before checking with
* linux-fsdevel@vger.kernel.org and linux-api@vger.kernel.org.
*/
#define FS_SECRM_FL 0x00000001 /* Secure deletion */
#define FS_UNRM_FL 0x00000002 /* Undelete */
......@@ -185,8 +205,8 @@ struct inodes_stat_t {
#define FS_DIRTY_FL 0x00000100
#define FS_COMPRBLK_FL 0x00000200 /* One or more compressed clusters */
#define FS_NOCOMP_FL 0x00000400 /* Don't compress */
#define FS_ECOMPR_FL 0x00000800 /* Compression error */
/* End compression flags --- maybe not all used */
#define FS_ENCRYPT_FL 0x00000800 /* Encrypted file */
#define FS_BTREE_FL 0x00001000 /* btree format dir */
#define FS_INDEX_FL 0x00001000 /* hash-indexed directory */
#define FS_IMAGIC_FL 0x00002000 /* AFS directory */
......@@ -194,9 +214,12 @@ struct inodes_stat_t {
#define FS_NOTAIL_FL 0x00008000 /* file tail should not be merged */
#define FS_DIRSYNC_FL 0x00010000 /* dirsync behaviour (directories only) */
#define FS_TOPDIR_FL 0x00020000 /* Top of directory hierarchies*/
#define FS_HUGE_FILE_FL 0x00040000 /* Reserved for ext4 */
#define FS_EXTENT_FL 0x00080000 /* Extents */
#define FS_DIRECTIO_FL 0x00100000 /* Use direct i/o */
#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_INLINE_DATA_FL 0x10000000 /* Reserved for ext4 */
#define FS_PROJINHERIT_FL 0x20000000 /* Create with parents projid */
#define FS_RESERVED_FL 0x80000000 /* reserved for ext2 lib */
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment