Add initial support for extended attribute blocks

7 files changed, 176 insertions, 2 deletions

diff --git a/lib/e2p/ChangeLog b/lib/e2p/ChangeLog
index 0df0008a..4b066268 100644
--- a/lib/e2p/ChangeLog
+++ b/lib/e2p/ChangeLog
@@ -1,5 +1,8 @@
 2001-06-23  Theodore Tso  <tytso@valinux.com>
 
+	* feature.c: Add entry in feature table to interpret
+		EXT2_FEATURE_COMPAT_EXT_ATTR.
+
 	* Release of E2fsprogs 1.22
 
 2001-06-15  Theodore Tso  <tytso@valinux.com>
diff --git a/lib/e2p/feature.c b/lib/e2p/feature.c
index c9d2427c..2586727c 100644
--- a/lib/e2p/feature.c
+++ b/lib/e2p/feature.c
@@ -29,6 +29,8 @@ static struct feature feature_list[] = {
 			"has_journal" },
 	{	E2P_FEATURE_COMPAT, EXT2_FEATURE_COMPAT_IMAGIC_INODES,
 			"imagic_inodes" },
+	{	E2P_FEATURE_COMPAT, EXT2_FEATURE_COMPAT_EXT_ATTR,
+			"ext_attr" },
 	{	E2P_FEATURE_COMPAT, EXT2_FEATURE_COMPAT_DIR_INDEX,
 			"dir_index" },
 	{	E2P_FEATURE_COMPAT, EXT2_FEATURE_COMPAT_RESIZE_INODE,
diff --git a/lib/ext2fs/ChangeLog b/lib/ext2fs/ChangeLog
index e9541663..43e23f66 100644
--- a/lib/ext2fs/ChangeLog
+++ b/lib/ext2fs/ChangeLog
@@ -1,5 +1,9 @@
 2001-06-23  Theodore Tso  <tytso@valinux.com>
 
+	* Makefile.in, ext_attr.c, ext2_attr.c, ext2fs.h: Add new files
+		ext2_ext_attr.h and ext_attr.c for extended attributes
+		support.
+
 	* Release of E2fsprogs 1.22
 
 2001-06-22  Theodore Tso  <tytso@valinux.com>
diff --git a/lib/ext2fs/Makefile.in b/lib/ext2fs/Makefile.in
index d5adcb67..948a8736 100644
--- a/lib/ext2fs/Makefile.in
+++ b/lib/ext2fs/Makefile.in
@@ -31,6 +31,7 @@ OBJS= $(DEBUGFS_LIB_OBJS) $(RESIZE_LIB_OBJS) $(E2IMAGE_LIB_OBJS) \
 	dirblock.o \
 	dir_iterate.o \
 	expanddir.o \
+	ext_attr.o \
 	finddev.o \
 	flushb.o \
 	freefs.o \
@@ -78,6 +79,7 @@ SRCS= ext2_err.c \
 	$(srcdir)/dir_iterate.c \
 	$(srcdir)/dupfs.c \
 	$(srcdir)/expanddir.c \
+	$(srcdir)/ext_attr.c \
 	$(srcdir)/fileio.c \
 	$(srcdir)/finddev.c \
 	$(srcdir)/flushb.c \
@@ -112,7 +114,7 @@ SRCS= ext2_err.c \
 	$(srcdir)/version.c \
 	$(srcdir)/write_bb_file.c
 
-HFILES= bitops.h ext2fs.h ext2_io.h ext2_fs.h
+HFILES= bitops.h ext2fs.h ext2_io.h ext2_fs.h ext2_ext_attr.h
 HFILES_IN=  ext2_err.h ext2_types.h
 
 LIBRARY= libext2fs
diff --git a/lib/ext2fs/ext2_ext_attr.h b/lib/ext2fs/ext2_ext_attr.h
new file mode 100644
index 00000000..bbc90d9f
--- /dev/null
+++ b/lib/ext2fs/ext2_ext_attr.h
@@ -0,0 +1,60 @@
+/*
+  File: linux/ext2_ext_attr.h
+
+  On-disk format of extended attributes for the ext2 filesystem.
+
+  (C) 2000 Andreas Gruenbacher, <a.gruenbacher@computer.org>
+*/
+
+#include <linux/config.h>
+
+/* Magic value in attribute blocks */
+#define EXT2_EXT_ATTR_MAGIC		0xEA010000
+
+/* Maximum number of references to one attribute block */
+#define EXT2_EXT_ATTR_REFCOUNT_MAX	1024
+
+struct ext2_ext_attr_header {
+	__u32	h_magic;	/* magic number for identification */
+	__u32	h_refcount;	/* reference count */
+	__u32	h_blocks;	/* number of disk blocks used */
+	__u32	h_hash;		/* hash value of all attributes */
+	__u32	h_reserved[4];	/* zero right now */
+};
+
+struct ext2_ext_attr_entry {
+	__u8	e_name_len;	/* length of name */
+	__u8	e_name_index;	/* index into table of names (n/i) */
+	__u16	e_value_offs;	/* offset in disk block of value */
+	__u32	e_value_block;	/* disk block attribute is stored on (n/i) */
+	__u32	e_value_size;	/* size of attribute value */
+	__u32	e_hash;		/* hash value of name and value */
+	char	e_name[0];	/* attribute name */
+};
+
+#define EXT2_EXT_ATTR_PAD_BITS		2
+#define EXT2_EXT_ATTR_PAD		(1<<EXT2_EXT_ATTR_PAD_BITS)
+#define EXT2_EXT_ATTR_ROUND		(EXT2_EXT_ATTR_PAD-1)
+#define EXT2_EXT_ATTR_LEN(name_len) \
+	(((name_len) + EXT2_EXT_ATTR_ROUND + \
+	sizeof(struct ext2_ext_attr_entry)) & ~EXT2_EXT_ATTR_ROUND)
+#define EXT2_EXT_ATTR_NEXT(entry) \
+	( (struct ext2_ext_attr_entry *)( \
+	  (char *)(entry) + EXT2_EXT_ATTR_LEN((entry)->e_name_len)) )
+#define EXT2_EXT_ATTR_SIZE(size) \
+	(((size) + EXT2_EXT_ATTR_ROUND) & ~EXT2_EXT_ATTR_ROUND)
+
+#ifdef __KERNEL__
+# ifdef CONFIG_EXT2_FS_EXT_ATTR
+extern int ext2_get_ext_attr(struct inode *, const char *, char *, size_t, int);
+extern int ext2_set_ext_attr(struct inode *, const char *, char *, size_t, int);
+extern void ext2_ext_attr_free_inode(struct inode *inode);
+extern void ext2_ext_attr_put_super(struct super_block *sb);
+extern int ext2_ext_attr_init(void);
+extern void ext2_ext_attr_done(void);
+# else
+#  define ext2_get_ext_attr NULL
+#  define ext2_set_ext_attr NULL
+# endif
+#endif  /* __KERNEL__ */
+
diff --git a/lib/ext2fs/ext2fs.h b/lib/ext2fs/ext2fs.h
index f89ccc7e..2b23e04a 100644
--- a/lib/ext2fs/ext2fs.h
+++ b/lib/ext2fs/ext2fs.h
@@ -402,7 +402,8 @@ typedef struct ext2_icount *ext2_icount_t;
  */
 #define EXT2_LIB_FEATURE_COMPAT_SUPP	(EXT2_FEATURE_COMPAT_DIR_PREALLOC|\
 					 EXT2_FEATURE_COMPAT_IMAGIC_INODES|\
-					 EXT3_FEATURE_COMPAT_HAS_JOURNAL)
+					 EXT3_FEATURE_COMPAT_HAS_JOURNAL|\
+					 EXT2_FEATURE_COMPAT_EXT_ATTR)
 
 /* This #ifdef is temporary until compression is fully supported */
 #ifdef ENABLE_COMPRESSION
@@ -607,6 +608,10 @@ extern errcode_t ext2fs_dup_handle(ext2_filsys src, ext2_filsys *dest);
 /* expanddir.c */
 extern errcode_t ext2fs_expand_dir(ext2_filsys fs, ext2_ino_t dir);
 
+/* ext_attr.c */
+void ext2fs_swap_ext_attr(ext2_filsys fs, char *to, char *from);
+extern errcode_t ext2fs_read_ext_attr(ext2_filsys fs, blk_t block, void *buf);
+extern errcode_t ext2fs_write_ext_attr(ext2_filsys fs, blk_t block, void *buf); 
 /* fileio.c */
 extern errcode_t ext2fs_file_open(ext2_filsys fs, ext2_ino_t ino,
 				  int flags, ext2_file_t *ret);
diff --git a/lib/ext2fs/ext_attr.c b/lib/ext2fs/ext_attr.c
new file mode 100644
index 00000000..480df36b
--- /dev/null
+++ b/lib/ext2fs/ext_attr.c
@@ -0,0 +1,98 @@
+/*
+ * ext_attr.c --- extended attribute blocks
+ * 
+ * Copyright (C) Andreas Gruenbacher, <a.gruenbacher@computer.org>
+ *
+ * %Begin-Header%
+ * This file may be redistributed under the terms of the GNU Public
+ * License.
+ * %End-Header%
+ */
+
+#include <stdio.h>
+#if HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+#include <string.h>
+#include <time.h>
+
+#include "ext2_fs.h"
+#include "ext2_ext_attr.h"
+
+#include "ext2fs.h"
+
+#ifdef EXT2FS_ENABLE_SWAPFS
+void ext2fs_swap_ext_attr(ext2_filsys fs, char *to, char *from)
+{
+	struct ext2_ext_attr_header *from_header =
+		(struct ext2_ext_attr_header *)from;
+	struct ext2_ext_attr_header *to_header =
+		(struct ext2_ext_attr_header *)to;
+	struct ext2_ext_attr_entry *from_entry, *to_entry;
+	char *from_end = (char *)from_header + fs->blocksize;
+	int n;
+
+	if (to_header != from_header)
+		memcpy(to_header, from_header, fs->blocksize);
+
+	to_header->h_magic    = ext2fs_swab32(from_header->h_magic);
+	to_header->h_blocks   = ext2fs_swab32(from_header->h_blocks);
+	to_header->h_refcount = ext2fs_swab32(from_header->h_refcount);
+	for (n=0; n<4; n++)
+		to_header->h_reserved[n] =
+			ext2fs_swab32(from_header->h_reserved[n]);
+	
+	from_entry = (struct ext2_ext_attr_entry *)(from_header+1);
+	to_entry   = (struct ext2_ext_attr_entry *)(to_header+1);
+	while ((char *)from_entry < from_end && *(__u32 *)from_entry) {
+		to_entry->e_value_offs  =	
+			ext2fs_swab16(from_entry->e_value_offs);
+		to_entry->e_value_block =	
+			ext2fs_swab32(from_entry->e_value_block);
+		to_entry->e_value_size  =	
+			ext2fs_swab32(from_entry->e_value_size);
+		from_entry = EXT2_EXT_ATTR_NEXT(from_entry);
+		to_entry   = EXT2_EXT_ATTR_NEXT(to_entry);
+	}
+}
+#endif
+
+errcode_t ext2fs_read_ext_attr(ext2_filsys fs, blk_t block, void *buf)
+{
+	errcode_t	retval;
+	struct ext2_ext_attr_entry *entry;
+
+ 	retval = io_channel_read_blk(fs->io, block, 1, buf);
+	if (retval)
+		return retval;
+#ifdef EXT2FS_ENABLE_SWAPFS
+	if ((fs->flags & (EXT2_FLAG_SWAP_BYTES|
+			  EXT2_FLAG_SWAP_BYTES_READ)) != 0)
+		ext2fs_swap_ext_attr(fs, buf, buf);
+#endif
+	return 0;
+}
+
+errcode_t ext2fs_write_ext_attr(ext2_filsys fs, blk_t block, void *inbuf)
+{
+	errcode_t	retval;
+	char		*p, *end, *write_buf;
+	char		*buf = NULL;
+	struct ext2_dir_entry *dirent;
+
+#ifdef EXT2FS_ENABLE_SWAPFS
+	if ((fs->flags & EXT2_FLAG_SWAP_BYTES) ||
+	    (fs->flags & EXT2_FLAG_SWAP_BYTES_WRITE)) {
+		retval = ext2fs_get_mem(fs->blocksize, (void **) &buf);
+		if (retval)
+			return retval;
+		write_buf = buf;
+		ext2fs_swap_ext_attr(fs, buf, inbuf);
+	} else
+#endif
+		write_buf = (char *) inbuf;
+ 	retval = io_channel_write_blk(fs->io, block, 1, write_buf);
+	if (buf)
+		ext2fs_free_mem((void **) &buf);
+	return retval;
+}