[PATCH 8/9] 48-bit block numbers for extended attributes

[Mingming Cao <cmm@us.ibm.com>]

As we are planning to support 48-bit block numbers for ext4,
we need to support 48-bit block numbers for extended attributes.
In the short term, we can do this by reuse (on-disk) 16-bit
padding (linux2.i_pad1 currently used only by "hurd") as high 
order bits for xattr. This patch basically does that.

Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>


---

 linux-2.6.18-rc4-ming/fs/ext4/inode.c         |    8 ++++++++
 linux-2.6.18-rc4-ming/include/linux/ext4_fs.h |    6 ++++--
 2 files changed, 12 insertions(+), 2 deletions(-)

diff -puN fs/ext4/inode.c~ext4_48bit_i_file_acl fs/ext4/inode.c
--- linux-2.6.18-rc4/fs/ext4/inode.c~ext4_48bit_i_file_acl	2006-08-09 15:42:05.848401839 -0700
+++ linux-2.6.18-rc4-ming/fs/ext4/inode.c	2006-08-09 15:42:05.858401920 -0700
@@ -2641,6 +2641,10 @@ void ext4_read_inode(struct inode * inod
 	ei->i_frag_size = raw_inode->i_fsize;
 #endif
 	ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl);
+	if ((sizeof(sector_t) > 4) &&
+	    (EXT4_SB(inode->i_sb)->s_es->s_creator_os != EXT4_OS_HURD))
+		ei->i_file_acl |=
+			((__u64)le16_to_cpu(raw_inode->i_file_acl_high)) << 32;
 	if (!S_ISREG(inode->i_mode)) {
 		ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl);
 	} else {
@@ -2774,6 +2778,10 @@ static int ext4_do_update_inode(handle_t
 	raw_inode->i_frag = ei->i_frag_no;
 	raw_inode->i_fsize = ei->i_frag_size;
 #endif
+	if ((sizeof(sector_t) > 4) &&
+	    (EXT4_SB(inode->i_sb)->s_es->s_creator_os != EXT4_OS_HURD))
+		raw_inode->i_file_acl_high =
+			cpu_to_le16((__u64)ei->i_file_acl >> 32);
 	raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl);
 	if (!S_ISREG(inode->i_mode)) {
 		raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl);
diff -puN include/linux/ext4_fs.h~ext4_48bit_i_file_acl include/linux/ext4_fs.h
--- linux-2.6.18-rc4/include/linux/ext4_fs.h~ext4_48bit_i_file_acl	2006-08-09 15:42:05.851401864 -0700
+++ linux-2.6.18-rc4-ming/include/linux/ext4_fs.h	2006-08-09 15:42:05.860401937 -0700
@@ -285,7 +285,7 @@ struct ext4_inode {
 		struct {
 			__u8	l_i_frag;	/* Fragment number */
 			__u8	l_i_fsize;	/* Fragment size */
-			__u16	i_pad1;
+			__u16	l_i_file_acl_high;
 			__le16	l_i_uid_high;	/* these 2 fields    */
 			__le16	l_i_gid_high;	/* were reserved2[0] */
 			__u32	l_i_reserved2;
@@ -301,7 +301,7 @@ struct ext4_inode {
 		struct {
 			__u8	m_i_frag;	/* Fragment number */
 			__u8	m_i_fsize;	/* Fragment size */
-			__u16	m_pad1;
+			__u16	m_i_file_acl_high;
 			__u32	m_i_reserved2[2];
 		} masix2;
 	} osd2;				/* OS dependent 2 */
@@ -315,6 +315,7 @@ struct ext4_inode {
 #define i_reserved1	osd1.linux1.l_i_reserved1
 #define i_frag		osd2.linux2.l_i_frag
 #define i_fsize		osd2.linux2.l_i_fsize
+#define i_file_acl_high	osd2.linux2.l_i_file_acl_high
 #define i_uid_low	i_uid
 #define i_gid_low	i_gid
 #define i_uid_high	osd2.linux2.l_i_uid_high
@@ -335,6 +336,7 @@ struct ext4_inode {
 #define i_reserved1	osd1.masix1.m_i_reserved1
 #define i_frag		osd2.masix2.m_i_frag
 #define i_fsize		osd2.masix2.m_i_fsize
+#define i_file_acl_high	osd2.masix2.m_i_file_acl_high
 #define i_reserved2	osd2.masix2.m_i_reserved2
 
 #endif /* defined(__KERNEL__) || defined(__linux__) */

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