[GFS2] Update ioctl() to new interface

This is designed as a fs independent way to set flags on a
particular inode. The values of the ioctl() and flags are
designed to be identical to the ext2/3 values. Assuming that
this plan is acceptable to people in general, the plan is to
then move other fs across to using the same set of #defines,
etc.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

3 files changed, 156 insertions, 102 deletions

diff --git a/fs/gfs2/ops_file.c b/fs/gfs2/ops_file.c
index ac8e123..db4484a 100644
--- a/fs/gfs2/ops_file.c
+++ b/fs/gfs2/ops_file.c
@@ -21,6 +21,7 @@
 #include <linux/gfs2_ondisk.h>
 #include <linux/ext2_fs.h>
 #include <linux/crc32.h>
+#include <linux/iflags.h>
 #include <asm/semaphore.h>
 #include <asm/uaccess.h>
 
@@ -536,110 +537,44 @@ static int gfs2_readdir(struct file *file, void *dirent, filldir_t filldir)
 	return error;
 }
 
-const struct gfs2_flag_eattr {
-	u32 flag;
-	u32 ext2;
-} gfs2_flag_eattrs[] = {
-	{
-		.flag = GFS2_DIF_IMMUTABLE,
-		.ext2 = EXT2_IMMUTABLE_FL,
-	}, {
-		.flag = GFS2_DIF_APPENDONLY,
-		.ext2 = EXT2_APPEND_FL,
-	}, {
-		.flag = GFS2_DIF_JDATA,
-		.ext2 = EXT2_JOURNAL_DATA_FL,
-	}, {
-		.flag = GFS2_DIF_EXHASH,
-		.ext2 = EXT2_INDEX_FL,
-	}, {
-		.flag = GFS2_DIF_EA_INDIRECT,
-	}, {
-		.flag = GFS2_DIF_DIRECTIO,
-	}, {
-		.flag = GFS2_DIF_NOATIME,
-		.ext2 = EXT2_NOATIME_FL,
-	}, {
-		.flag = GFS2_DIF_SYNC,
-		.ext2 = EXT2_SYNC_FL,
-	}, {
-		.flag = GFS2_DIF_SYSTEM,
-	}, {
-		.flag = GFS2_DIF_TRUNC_IN_PROG,
-	}, {
-		.flag = GFS2_DIF_INHERIT_JDATA,
-	}, {
-		.flag = GFS2_DIF_INHERIT_DIRECTIO,
-	}, {
-	},
+static const u32 iflags_to_gfs2[32] = {
+	[iflag_Sync] = GFS2_DIF_SYNC,
+	[iflag_Immutable] = GFS2_DIF_IMMUTABLE,
+	[iflag_Append] = GFS2_DIF_APPENDONLY,
+	[iflag_NoAtime] = GFS2_DIF_NOATIME,
+	[iflag_Index] = GFS2_DIF_EXHASH,
+	[iflag_JournalData] = GFS2_DIF_JDATA,
+	[iflag_DirectIO] = GFS2_DIF_DIRECTIO,
+	[iflag_InheritDirectIO] = GFS2_DIF_INHERIT_DIRECTIO,
+	[iflag_InheritJdata] = GFS2_DIF_INHERIT_JDATA,
 };
 
-static const struct gfs2_flag_eattr *get_by_ext2(u32 ext2)
-{
-	const struct gfs2_flag_eattr *p = gfs2_flag_eattrs;
-	for(; p->flag; p++) {
-		if (ext2 == p->ext2)
-			return p;
-	}
-	return NULL;
-}
-
-static const struct gfs2_flag_eattr *get_by_gfs2(u32 gfs2)
-{
-	const struct gfs2_flag_eattr *p = gfs2_flag_eattrs;
-	for(; p->flag; p++) {
-		if (gfs2 == p->flag)
-			return p;
-	}
-	return NULL;
-}
-
-static u32 gfs2_flags_to_ext2(u32 gfs2)
-{
-	const struct gfs2_flag_eattr *ea;
-	u32 ext2 = 0;
-	u32 mask = 1;
-
-	for(; mask != 0; mask <<=1) {
-		if (mask & gfs2) {
-			ea = get_by_gfs2(mask);
-			if (ea)
-				ext2 |= ea->ext2;
-		}
-	}
-	return ext2;
-}
-
-static int gfs2_flags_from_ext2(u32 *gfs2, u32 ext2)
-{
-	const struct gfs2_flag_eattr *ea;
-	u32 mask = 1;
-
-	for(; mask != 0; mask <<= 1) {
-		if (mask & ext2) {
-			ea = get_by_ext2(mask);
-			if (ea == NULL)
-				return -EINVAL;
-			*gfs2 |= ea->flag;
-		}
-	}
-	return 0;
-}
+static const u32 gfs2_to_iflags[32] = {
+	[gfs2fl_Sync] = IFLAG_SYNC,
+	[gfs2fl_Immutable] = IFLAG_IMMUTABLE,
+	[gfs2fl_AppendOnly] = IFLAG_APPEND,
+	[gfs2fl_NoAtime] = IFLAG_NOATIME,
+	[gfs2fl_ExHash] = IFLAG_INDEX,
+	[gfs2fl_Jdata] = IFLAG_JOURNAL_DATA,
+	[gfs2fl_Directio] = IFLAG_DIRECTIO,
+	[gfs2fl_InheritDirectio] = IFLAG_INHERITDIRECTIO,
+	[gfs2fl_InheritJdata] = IFLAG_INHERITJDATA,
+};
 
-static int get_ext2_flags(struct inode *inode, u32 __user *ptr)
+static int gfs2_get_flags(struct inode *inode, u32 __user *ptr)
 {
 	struct gfs2_inode *ip = inode->u.generic_ip;
 	struct gfs2_holder gh;
 	int error;
-	u32 ext2;
+	u32 iflags;
 
 	gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME, &gh);
 	error = gfs2_glock_nq_m_atime(1, &gh);
 	if (error)
 		return error;
 
-	ext2 = gfs2_flags_to_ext2(ip->i_di.di_flags);
-	if (put_user(ext2, ptr))
+	iflags = iflags_cvt(gfs2_to_iflags, ip->i_di.di_flags);
+	if (put_user(iflags, ptr))
 		error = -EFAULT;
 
 	gfs2_glock_dq_m(1, &gh);
@@ -665,7 +600,7 @@ static int get_ext2_flags(struct inode *inode, u32 __user *ptr)
  * @mask: Indicates which flags are valid
  *
  */
-static int gfs2_set_flags(struct inode *inode, u32 flags, u32 mask)
+static int do_gfs2_set_flags(struct inode *inode, u32 flags, u32 mask)
 {
 	struct gfs2_inode *ip = inode->u.generic_ip;
 	struct buffer_head *bh;
@@ -717,24 +652,23 @@ out:
 	return error;
 }
 
-static int set_ext2_flags(struct inode *inode, u32 __user *ptr)
+static int gfs2_set_flags(struct inode *inode, u32 __user *ptr)
 {
-	u32 ext2, gfs2;
-	if (get_user(ext2, ptr))
+	u32 iflags, gfsflags;
+	if (get_user(iflags, ptr))
 		return -EFAULT;
-	if (gfs2_flags_from_ext2(&gfs2, ext2))
-		return -EINVAL;
-	return gfs2_set_flags(inode, gfs2, ~0);
+	gfsflags = iflags_cvt(iflags_to_gfs2, iflags);
+	return do_gfs2_set_flags(inode, gfsflags, ~0);
 }
 
 int gfs2_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
 	       unsigned long arg)
 {
 	switch(cmd) {
-	case EXT2_IOC_GETFLAGS:
-		return get_ext2_flags(inode, (u32 __user *)arg);
-	case EXT2_IOC_SETFLAGS:
-		return set_ext2_flags(inode, (u32 __user *)arg);
+	case IFLAGS_GET_IOC:
+		return gfs2_get_flags(inode, (u32 __user *)arg);
+	case IFLAGS_SET_IOC:
+		return gfs2_set_flags(inode, (u32 __user *)arg);
 	}
 	return -ENOTTY;
 }
diff --git a/include/linux/gfs2_ondisk.h b/include/linux/gfs2_ondisk.h
index a5fb4f9..3ab4091 100644
--- a/include/linux/gfs2_ondisk.h
+++ b/include/linux/gfs2_ondisk.h
@@ -197,6 +197,22 @@ struct gfs2_quota {
 #define DT2IF(dt) (((dt) << 12) & S_IFMT)
 #define IF2DT(sif) (((sif) & S_IFMT) >> 12)
 
+enum {
+	gfs2fl_Jdata		= 0,
+	gfs2fl_ExHash		= 1,
+	gfs2fl_Unused		= 2,
+	gfs2fl_EaIndirect	= 3,
+	gfs2fl_Directio		= 4,
+	gfs2fl_Immutable	= 5,
+	gfs2fl_AppendOnly	= 6,
+	gfs2fl_NoAtime		= 7,
+	gfs2fl_Sync		= 8,
+	gfs2fl_System		= 9,
+	gfs2fl_TruncInProg	= 29,
+	gfs2fl_InheritDirectio	= 30,
+	gfs2fl_InheritJdata	= 31,
+};
+
 /* Dinode flags */
 #define GFS2_DIF_JDATA			0x00000001
 #define GFS2_DIF_EXHASH			0x00000002
diff --git a/include/linux/iflags.h b/include/linux/iflags.h
new file mode 100644
index 0000000..1b4d9ef
--- /dev/null
+++ b/include/linux/iflags.h
@@ -0,0 +1,104 @@
+#ifndef _LINUX_IFLAGS_H
+#define _LINUX_IFLAGS_H
+
+/*
+ * A universal set of inode flags.
+ *
+ * Originally taken from ext2/3 with additions for other filesystems.
+ * Filesystems supporting this interface should interoperate with
+ * the lsattr and chattr command line tools.
+ *
+ * This interface is supported in whole or in part by:
+ * ext2
+ * ext3
+ * xfs
+ * jfs
+ * gfs2
+ *
+ */
+
+#define IFLAGS_GET_IOC		_IOR('f', 1, long)
+#define IFLAGS_SET_IOC		_IOW('f', 2, long)
+
+/*
+ * These values are provided for use as indices of an array
+ * for use with the iflags_cvt function below
+ */
+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 */
+
+#ifdef __KERNEL__
+/**
+ * iflags_cvt
+ * @table: A table of 32 u32 flags
+ * @val: a 32 bit value to convert
+ *
+ * This function can be used to convert between IFLAGS values and
+ * the filesystem's own flags values.
+ *
+ * Returns: the converted flags
+ */
+static inline u32 iflags_cvt(const u32 *table, u32 val)
+{
+	u32 res = 0;
+	while(val) {
+		if (val & 1)
+			res |= *table;
+		table++;
+		val >>= 1;
+	}
+	return res;
+}
+#endif /* __KERNEL__ */
+
+#endif /* _LINUX_IFLAGS_H */