[RFC 2/2] JBD: blocks reservation fix for large block support

Mingming Cao
2007-09-01T00:12:21Z

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@us.ibm.com>

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;
}

/*