The blocks per page could be less or quals to 1 with the large block support in VM. The patch fixed the way to calculate the number of blocks to reserve in journal in the case blocksize > pagesize. Signed-off-by: Mingming Cao <cmm@xxxxxxxxxx> Index: my2.6/fs/jbd/journal.c =================================================================== --- my2.6.orig/fs/jbd/journal.c 2007-08-31 13:27:16.000000000 -0700 +++ my2.6/fs/jbd/journal.c 2007-08-31 13:28:18.000000000 -0700 @@ -1611,7 +1611,12 @@ void journal_ack_err(journal_t *journal) int journal_blocks_per_page(struct inode *inode) { - return 1 << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits); + int bits = PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits; + + if (bits > 0) + return 1 << bits; + else + return 1; } /* Index: my2.6/fs/jbd2/journal.c =================================================================== --- my2.6.orig/fs/jbd2/journal.c 2007-08-31 13:32:21.000000000 -0700 +++ my2.6/fs/jbd2/journal.c 2007-08-31 13:32:30.000000000 -0700 @@ -1612,7 +1612,12 @@ void jbd2_journal_ack_err(journal_t *jou int jbd2_journal_blocks_per_page(struct inode *inode) { - return 1 << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits); + int bits = PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits; + + if (bits > 0) + return 1 << bits; + else + return 1; } /* - To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html