xfs: nothing special about 1-block log sector

There are a number of places where a log sector size of 1 uses
special case code.  The round_up() and round_down() macros
produce the correct result even when the log sector size is 1, and
this eliminates the need for treating this as a special case.

Signed-off-by: Alex Elder <aelder@sgi.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
This commit is contained in:
Alex Elder 2010-04-13 15:21:13 +10:00
parent ff30a6221d
commit 36adecff50

View file

@ -77,6 +77,11 @@ xlog_buf_bbcount_valid(
return bbcount > 0 && bbcount <= log->l_logBBsize; return bbcount > 0 && bbcount <= log->l_logBBsize;
} }
/*
* Allocate a buffer to hold log data. The buffer needs to be able
* to map to a range of nbblks basic blocks at any valid (basic
* block) offset within the log.
*/
STATIC xfs_buf_t * STATIC xfs_buf_t *
xlog_get_bp( xlog_get_bp(
xlog_t *log, xlog_t *log,
@ -89,11 +94,26 @@ xlog_get_bp(
return NULL; return NULL;
} }
if (log->l_sectbb_log) { /*
if (nbblks > 1) * We do log I/O in units of log sectors (a power-of-2
nbblks += xlog_sectbb(log); * multiple of the basic block size), so we round up the
nbblks = round_up(nbblks, xlog_sectbb(log)); * requested size to acommodate the basic blocks required
} * for complete log sectors.
*
* In addition, the buffer may be used for a non-sector-
* aligned block offset, in which case an I/O of the
* requested size could extend beyond the end of the
* buffer. If the requested size is only 1 basic block it
* will never straddle a sector boundary, so this won't be
* an issue. Nor will this be a problem if the log I/O is
* done in basic blocks (sector size 1). But otherwise we
* extend the buffer by one extra log sector to ensure
* there's space to accomodate this possiblility.
*/
if (nbblks > 1 && log->l_sectbb_log)
nbblks += xlog_sectbb(log);
nbblks = round_up(nbblks, xlog_sectbb(log));
return xfs_buf_get_noaddr(BBTOB(nbblks), log->l_mp->m_logdev_targp); return xfs_buf_get_noaddr(BBTOB(nbblks), log->l_mp->m_logdev_targp);
} }
@ -142,10 +162,8 @@ xlog_bread_noalign(
return EFSCORRUPTED; return EFSCORRUPTED;
} }
if (log->l_sectbb_log) { blk_no = round_down(blk_no, xlog_sectbb(log));
blk_no = round_down(blk_no, xlog_sectbb(log)); nbblks = round_up(nbblks, xlog_sectbb(log));
nbblks = round_up(nbblks, xlog_sectbb(log));
}
ASSERT(nbblks > 0); ASSERT(nbblks > 0);
ASSERT(BBTOB(nbblks) <= XFS_BUF_SIZE(bp)); ASSERT(BBTOB(nbblks) <= XFS_BUF_SIZE(bp));
@ -204,10 +222,8 @@ xlog_bwrite(
return EFSCORRUPTED; return EFSCORRUPTED;
} }
if (log->l_sectbb_log) { blk_no = round_down(blk_no, xlog_sectbb(log));
blk_no = round_down(blk_no, xlog_sectbb(log)); nbblks = round_up(nbblks, xlog_sectbb(log));
nbblks = round_up(nbblks, xlog_sectbb(log));
}
ASSERT(nbblks > 0); ASSERT(nbblks > 0);
ASSERT(BBTOB(nbblks) <= XFS_BUF_SIZE(bp)); ASSERT(BBTOB(nbblks) <= XFS_BUF_SIZE(bp));