On Apr 21, 2006 17:13 +0100, Steven Whitehouse wrote:
> This also includes a new header file, iflags.h which is designed to
> abstract the (originally ext2 only, but now used by many different fs)
> get/set flags ioctl by having one central place in which to register
> filesystem flags. Given favourable reviews, I'll submit some patches to
> update the other fileststems to define their flags in terms of those
> in iflags.h. Note that this doesn't change the interface of the other
> filesystems since the values of the flags are identical to those
> previously defined.
>
> To the best of my knowledge, GFS2 is the only filesystem which requires
> the addition of flags above and beyond those defined by ext2/3 so if
> there are others and we've clashed with them, please let me know.
> --- /dev/null
> +++ b/include/linux/iflags.h
> @@ -0,0 +1,104 @@
> +enum {
> + iflag_SecureRm = 0, /* Secure deletion */
> + iflag_Unrm = 1, /* Undelete */
> + iflag_Compress = 2, /* Compress file */
> + iflag_Sync = 3, /* Synchronous updates */
> + iflag_Immutable = 4, /* Immutable */
> + iflag_Append = 5, /* Append */
> + iflag_NoDump = 6, /* Don't dump file */
> + iflag_NoAtime = 7, /* No atime updates */
> + /* Reserved for compression usage */
> + iflag_Dirty = 8,
> + iflag_ComprBlk = 9, /* One or more compressed clusters */
> + iflag_NoComp = 10, /* Don't compress */
> + iflag_Ecompr = 11, /* Compression error */
> + /* End of compression flags */
> + iflag_Btree = 12, /* btree format dir */
> + iflag_Index = 12, /* hash-indexed directory */
> + iflag_Imagic = 13, /* AFS directory */
> + iflag_JournalData = 14, /* file data should be journaled */
> + iflag_NoTail = 15, /* file tail should not be merged */
> + iflag_DirSync = 16, /* dirsync behaviour */
> + iflag_TopDir = 17, /* Top of directory hierarchies */
> + iflag_DirectIO = 18, /* Always use direct I/O on this file */
> + iflag_InheritDirectIO = 19, /* Set DirectIO on new files in dir */
> + iflag_InheritJdata = 20, /* Set JournalData on create in dir */
> + iflag_Reserved = 31 /* reserved for ext2/3 lib */
> +};
> +
> +#define __IFL(x) (1<<(iflag_##x))
> +#define IFLAG_SECRM __IFL(SecureRm) /* 0x00000001 */
> +#define IFLAG_UNRM __IFL(Unrm) /* 0x00000002 */
> +#define IFLAG_COMPR __IFL(Compr) /* 0x00000004 */
> +#define IFLAG_SYNC __IFL(Sync) /* 0x00000008 */
> +#define IFLAG_IMMUTABLE __IFL(Immutable) /* 0x00000010 */
> +#define IFLAG_APPEND __IFL(Append) /* 0x00000020 */
> +#define IFLAG_NODUMP __IFL(NoDump) /* 0x00000040 */
> +#define IFLAG_NOATIME __IFL(NoAtime) /* 0x00000080 */
> +#define IFLAG_DIRTY __IFL(Dirty) /* 0x00000100 */
> +#define IFLAG_COMPRBLK __IFL(ComprBlk) /* 0x00000200 */
> +#define IFLAG_NOCOMP __IFL(NoComp) /* 0x00000400 */
> +#define IFLAG_ECOMPR __IFL(Ecompr) /* 0x00000800 */
> +#define IFLAG_BTREE __IFL(Btree) /* 0x00001000 */
> +#define IFLAG_INDEX __IFL(Index) /* 0x00001000 */
> +#define IFLAG_IMAGIC __IFL(Imagic) /* 0x00002000 */
> +#define IFLAG_JOURNAL_DATA __IFL(JournalData) /* 0x00004000 */
> +#define IFLAG_NOTAIL __IFL(NoTail) /* 0x00008000 */
> +#define IFLAG_DIRSYNC __IFL(DirSync) /* 0x00010000 */
> +#define IFLAG_TOPDIR __IFL(TopDir) /* 0x00020000 */
> +#define IFLAG_DIRECTIO __IFL(DirectIO) /* 0x00040000 */
> +#define IFLAG_INHERITDIRECTIO __IFL(InheritDirectIO) /* 0x00080000 */
> +#define IFLAG_INHERITJDATA __IFL(InheritJdata) /* 0x00100000 */
> +#define IFLAG_RESERVED __IFL(Reserved) /* 0x80000000 */
Actually, the 0x0080000 flag has been reserved by e2fsprogs for ext3
extents for a while already. AFAICS, there are no other flags in the
current e2fsprogs that aren't listed above.
The other tidbit is that new ext2/ext3 files generally inherit the flags
from their parent directory, so it isn't clear if there is really a need
for a distinction between DIRECTIO and INHERIT_DIRECTIO, and similarly
JDATA and INHERIT_JDATA? Generally, I'd think that JDATA isn't meaningful
on directories (since they are metadata and journaled anyways), nor is
DIRECTIO so their only meaning on a directory is "INHERIT for new files".
Cheers, Andreas
--
Andreas Dilger
Principal Software Engineer
Cluster File Systems, Inc.
-
To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
