Commit e4fca01e authored by Pekka Enberg's avatar Pekka Enberg Committed by Linus Torvalds
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[PATCH] ext2: fsid for statvfs 

Update ext2_statfs to return an FSID that is a 64 bit XOR of the 128 bit
filesystem UUID as suggested by Andreas Dilger.  See the following Bugzilla
entry for details:

  http://bugzilla.kernel.org/show_bug.cgi?id=136



Cc: Andreas Dilger <adilger@clusterfs.com>
Cc: Stephen Tweedie <sct@redhat.com>
Signed-off-by: default avatarPekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 317a40ac

fs/ext2/super.c

+12 −6
Original line number Diff line number Diff line
@@ -1090,8 +1090,10 @@ static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf) 
{

	struct super_block *sb = dentry->d_sb;

	struct ext2_sb_info *sbi = EXT2_SB(sb);

	struct ext2_super_block *es = sbi->s_es;

	unsigned long overhead;

	int i;

	u64 fsid;



	if (test_opt (sb, MINIX_DF))

		overhead = 0;
@@ -1104,7 +1106,7 @@ static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf) 
		 * All of the blocks before first_data_block are

		 * overhead

		 */

		overhead = le32_to_cpu(sbi->s_es->s_first_data_block);

		overhead = le32_to_cpu(es->s_first_data_block);



		/*

		 * Add the overhead attributed to the superblock and
@@ -1125,14 +1127,18 @@ static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf) 


	buf->f_type = EXT2_SUPER_MAGIC;

	buf->f_bsize = sb->s_blocksize;

	buf->f_blocks = le32_to_cpu(sbi->s_es->s_blocks_count) - overhead;

	buf->f_blocks = le32_to_cpu(es->s_blocks_count) - overhead;

	buf->f_bfree = ext2_count_free_blocks(sb);

	buf->f_bavail = buf->f_bfree - le32_to_cpu(sbi->s_es->s_r_blocks_count);

	if (buf->f_bfree < le32_to_cpu(sbi->s_es->s_r_blocks_count))

	buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);

	if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))

		buf->f_bavail = 0;

	buf->f_files = le32_to_cpu(sbi->s_es->s_inodes_count);

	buf->f_files = le32_to_cpu(es->s_inodes_count);

	buf->f_ffree = ext2_count_free_inodes(sb);

	buf->f_namelen = EXT2_NAME_LEN;

	fsid = le64_to_cpup((void *)es->s_uuid) ^

	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));

	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;

	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;

	return 0;

}

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