minix zmap block counts calculation fix
authorQi Yong <qiyong@fc-cn.com>
Fri, 8 Aug 2014 21:20:29 +0000 (14:20 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 8 Aug 2014 22:57:20 +0000 (15:57 -0700)
The original minix zmap blocks calculation was correct, in the formula of:

sbi->s_nzones - sbi->s_firstdatazone + 1

It is

sp->s_zones - (sp->s_firstdatazone - 1)

in the minix3 source code.

But a later commit 016e8d44bc06 ("fs/minix: Verify bitmap block counts
before mounting") has changed it unfortunately as:

  sbi->s_nzones - (sbi->s_firstdatazone + 1)

This would show free blocks one block less than the real when the total
data blocks are in "full zmap blocks plus one".

This patch corrects that zmap blocks calculation and tidy a printk
message while at it.

Signed-off-by: Qi Yong <qiyong@fc-cn.com>
Cc: Josh Boyer <jwboyer@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs/minix/bitmap.c
fs/minix/inode.c

index 4bc50da..742942a 100644 (file)
@@ -96,7 +96,7 @@ int minix_new_block(struct inode * inode)
 unsigned long minix_count_free_blocks(struct super_block *sb)
 {
        struct minix_sb_info *sbi = minix_sb(sb);
-       u32 bits = sbi->s_nzones - (sbi->s_firstdatazone + 1);
+       u32 bits = sbi->s_nzones - sbi->s_firstdatazone + 1;
 
        return (count_free(sbi->s_zmap, sb->s_blocksize, bits)
                << sbi->s_log_zone_size);
index f007a33..3f57af1 100644 (file)
@@ -267,12 +267,12 @@ static int minix_fill_super(struct super_block *s, void *data, int silent)
        block = minix_blocks_needed(sbi->s_ninodes, s->s_blocksize);
        if (sbi->s_imap_blocks < block) {
                printk("MINIX-fs: file system does not have enough "
-                               "imap blocks allocated.  Refusing to mount\n");
+                               "imap blocks allocated.  Refusing to mount.\n");
                goto out_no_bitmap;
        }
 
        block = minix_blocks_needed(
-                       (sbi->s_nzones - (sbi->s_firstdatazone + 1)),
+                       (sbi->s_nzones - sbi->s_firstdatazone + 1),
                        s->s_blocksize);
        if (sbi->s_zmap_blocks < block) {
                printk("MINIX-fs: file system does not have enough "