JFS: ext2 inode attributes for jfs

ext2 inode attributes with relevance for jfs:

'a' 	EXT2_APPEND_FL       -> append only
'i' 	EXT2_IMMUTABLE_FL    -> immutable file
's' 	EXT2_SECRM_FL	     -> zero file
'u' 	EXT2_UNRM_FL	     -> allow for unrm
'A' 	EXT2_NOATIME_FL      -> no access time
'D' 	EXT2_DIRSYNC_FL      -> dirsync
'S' 	EXT2_SYNC_FL	     -> sync

overview of jfs flags (partially for OS/2)

value	   (OS/2)	Linux	ext2 attrs
------------------------------------------------
0x00010000 IFJOURNAL	-
0x00020000 ISPARSE  	used
0x00040000 INLINEEA 	used
0x00080000 -	    	-	JFS_NOATIME_FL

0x00100000 -	    	-	JFS_DIRSYNC_FL
0x00200000 -	    	-	JFS_SYNC_FL
0x00400000 -	    	-	JFS_SECRM_FL
0x00800000 ISWAPFILE	-	JFS_UNRM_FL

0x01000000 -	    	-	JFS_APPEND_FL
0x02000000 IREADONLY	-	JFS_IMMUTABLE_FL
0x04000000 IHIDDEN  	-	-
0x08000000 ISYSTEM  	-	-

0x10000000 -	    	-
0x20000000 IDIRECTORY	used
0x40000000 IARCHIVE 	-
0x80000000 INEWNAME 	-

the implementation is straight forward, except
for the fact that the attributes have to be mapped
to match with the ext2 ones to avoid a separate
tool for manipulating them (this could be avoided
when using a separate flag field in the on-disk
representation, but the overhead is minimal)

a special jfs_ioctl is added to allow for the new
JFS_IOC_GETFLAGS and JFS_IOC_SETFLAGS calls.

a helper function jfs_set_inode_flags() to transfer
the flags from the on-disk version to the inode

minor changes to allow flag inheritance on inode
creation, as well as a cleanup of the on-disk
flags (including the new ones)

beforementioned helper to map between ext2 and jfs
versions of the new flags ...

the JFS_SECRM_FL and JFS_UNRM_FL are not done yet
and I'm not 100% sure they are worth the effort,
the rest seems to work out of the box ...

Signed-off-by: Herbert Poetzl <herbert@13thfloor.at>
Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>

7 files changed, 69 insertions, 8 deletions

diff --git a/fs/jfs/Makefile b/fs/jfs/Makefile
index 6f1e0e9..3adb639 100644
--- a/fs/jfs/Makefile
+++ b/fs/jfs/Makefile
@@ -8,7 +8,8 @@ jfs-y    := super.o file.o inode.o namei.o jfs_mount.o jfs_umount.o \
 	    jfs_xtree.o jfs_imap.o jfs_debug.o jfs_dmap.o \
 	    jfs_unicode.o jfs_dtree.o jfs_inode.o \
 	    jfs_extent.o symlink.o jfs_metapage.o \
-	    jfs_logmgr.o jfs_txnmgr.o jfs_uniupr.o resize.o xattr.o
+	    jfs_logmgr.o jfs_txnmgr.o jfs_uniupr.o \
+	    resize.o xattr.o ioctl.o
 
 jfs-$(CONFIG_JFS_POSIX_ACL) += acl.o
 
diff --git a/fs/jfs/file.c b/fs/jfs/file.c
index c2c19c9..e1ac6e4 100644
--- a/fs/jfs/file.c
+++ b/fs/jfs/file.c
@@ -113,4 +113,5 @@ struct file_operations jfs_file_operations = {
  	.sendfile	= generic_file_sendfile,
 	.fsync		= jfs_fsync,
 	.release	= jfs_release,
+	.ioctl		= jfs_ioctl,
 };
diff --git a/fs/jfs/inode.c b/fs/jfs/inode.c
index d7834a9..51a5fed 100644
--- a/fs/jfs/inode.c
+++ b/fs/jfs/inode.c
@@ -55,6 +55,7 @@ void jfs_read_inode(struct inode *inode)
 		inode->i_op = &jfs_file_inode_operations;
 		init_special_inode(inode, inode->i_mode, inode->i_rdev);
 	}
+	jfs_set_inode_flags(inode);
 }
 
 /*
diff --git a/fs/jfs/jfs_dinode.h b/fs/jfs/jfs_dinode.h
index 580a325..9f2572a 100644
--- a/fs/jfs/jfs_dinode.h
+++ b/fs/jfs/jfs_dinode.h
@@ -139,13 +139,36 @@ struct dinode {
 
 /* more extended mode bits: attributes for OS/2 */
 #define IREADONLY	0x02000000	/* no write access to file */
-#define IARCHIVE	0x40000000	/* file archive bit */
-#define ISYSTEM		0x08000000	/* system file */
 #define IHIDDEN		0x04000000	/* hidden file */
-#define IRASH		0x4E000000	/* mask for changeable attributes */
-#define INEWNAME	0x80000000	/* non-8.3 filename format */
+#define ISYSTEM		0x08000000	/* system file */
+
 #define IDIRECTORY	0x20000000	/* directory (shadow of real bit) */
+#define IARCHIVE	0x40000000	/* file archive bit */
+#define INEWNAME	0x80000000	/* non-8.3 filename format */
+
+#define IRASH		0x4E000000	/* mask for changeable attributes */
 #define ATTRSHIFT	25	/* bits to shift to move attribute
 				   specification to mode position */
 
+/* extended attributes for Linux */
+
+#define JFS_NOATIME_FL		0x00080000 /* do not update atime */
+
+#define JFS_DIRSYNC_FL		0x00100000 /* dirsync behaviour */
+#define JFS_SYNC_FL		0x00200000 /* Synchronous updates */
+#define JFS_SECRM_FL		0x00400000 /* Secure deletion */
+#define JFS_UNRM_FL		0x00800000 /* allow for undelete */
+
+#define JFS_APPEND_FL		0x01000000 /* writes to file may only append */
+#define JFS_IMMUTABLE_FL	0x02000000 /* Immutable file */
+
+#define JFS_FL_USER_VISIBLE	0x03F80000
+#define JFS_FL_USER_MODIFIABLE	0x03F80000
+#define JFS_FL_INHERIT		0x03C80000
+
+/* These are identical to EXT[23]_IOC_GETFLAGS/SETFLAGS */
+#define JFS_IOC_GETFLAGS	_IOR('f', 1, long)
+#define JFS_IOC_SETFLAGS	_IOW('f', 2, long)
+
+
 #endif /*_H_JFS_DINODE */
diff --git a/fs/jfs/jfs_inode.c b/fs/jfs/jfs_inode.c
index 2af5efb..ae2772c 100644
--- a/fs/jfs/jfs_inode.c
+++ b/fs/jfs/jfs_inode.c
@@ -25,6 +25,26 @@
 #include "jfs_dinode.h"
 #include "jfs_debug.h"
 
+
+void jfs_set_inode_flags(struct inode *inode)
+{
+	unsigned int flags = JFS_IP(inode)->mode2;
+
+	inode->i_flags &= ~(S_IMMUTABLE | S_APPEND |
+		S_NOATIME | S_DIRSYNC | S_SYNC);
+
+	if (flags & JFS_IMMUTABLE_FL)
+		inode->i_flags |= S_IMMUTABLE;
+	if (flags & JFS_APPEND_FL)
+		inode->i_flags |= S_APPEND;
+	if (flags & JFS_NOATIME_FL)
+		inode->i_flags |= S_NOATIME;
+	if (flags & JFS_DIRSYNC_FL)
+		inode->i_flags |= S_DIRSYNC;
+	if (flags & JFS_SYNC_FL)
+		inode->i_flags |= S_SYNC;
+}
+
 /*
  * NAME:	ialloc()
  *
@@ -74,10 +94,20 @@ struct inode *ialloc(struct inode *parent, umode_t mode)
 	}
 
 	inode->i_mode = mode;
-	if (S_ISDIR(mode))
-		jfs_inode->mode2 = IDIRECTORY | mode;
+	/* inherit flags from parent */
+	jfs_inode->mode2 = JFS_IP(parent)->mode2 & JFS_FL_INHERIT;
+
+	if (S_ISDIR(mode)) {
+		jfs_inode->mode2 |= IDIRECTORY;
+		jfs_inode->mode2 &= ~JFS_DIRSYNC_FL;
+	}
+	else if (S_ISLNK(mode))
+		jfs_inode->mode2 &=
+			~(JFS_IMMUTABLE_FL|JFS_APPEND_FL);
 	else
-		jfs_inode->mode2 = INLINEEA | ISPARSE | mode;
+		jfs_inode->mode2 |= INLINEEA | ISPARSE;
+	jfs_inode->mode2 |= mode;
+
 	inode->i_blksize = sb->s_blocksize;
 	inode->i_blocks = 0;
 	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
@@ -98,6 +128,7 @@ struct inode *ialloc(struct inode *parent, umode_t mode)
 	jfs_inode->atlhead = 0;
 	jfs_inode->atltail = 0;
 	jfs_inode->xtlid = 0;
+	jfs_set_inode_flags(inode);
 
 	jfs_info("ialloc returns inode = 0x%p\n", inode);
 
diff --git a/fs/jfs/jfs_inode.h b/fs/jfs/jfs_inode.h
index b54bac5..095d471 100644
--- a/fs/jfs/jfs_inode.h
+++ b/fs/jfs/jfs_inode.h
@@ -20,6 +20,8 @@
 
 extern struct inode *ialloc(struct inode *, umode_t);
 extern int jfs_fsync(struct file *, struct dentry *, int);
+extern int jfs_ioctl(struct inode *, struct file *,
+			unsigned int, unsigned long);
 extern void jfs_read_inode(struct inode *);
 extern int jfs_commit_inode(struct inode *, int);
 extern int jfs_write_inode(struct inode*, int);
@@ -29,6 +31,7 @@ extern void jfs_truncate(struct inode *);
 extern void jfs_truncate_nolock(struct inode *, loff_t);
 extern void jfs_free_zero_link(struct inode *);
 extern struct dentry *jfs_get_parent(struct dentry *dentry);
+extern void jfs_set_inode_flags(struct inode *);
 
 extern struct address_space_operations jfs_aops;
 extern struct inode_operations jfs_dir_inode_operations;
diff --git a/fs/jfs/namei.c b/fs/jfs/namei.c
index ed4d170..309cee5 100644
--- a/fs/jfs/namei.c
+++ b/fs/jfs/namei.c
@@ -1523,6 +1523,7 @@ struct file_operations jfs_dir_operations = {
 	.read		= generic_read_dir,
 	.readdir	= jfs_readdir,
 	.fsync		= jfs_fsync,
+	.ioctl		= jfs_ioctl,
 };
 
 static int jfs_ci_hash(struct dentry *dir, struct qstr *this)