Commit b394e43e authored by Lachlan McIlroy's avatar Lachlan McIlroy Committed by Tim Shimmin
Browse files

[XFS] Avoid replaying inode buffer initialisation log items if on-disk version is newer. 



SGI-PV: 969656
SGI-Modid: xfs-linux-melb:xfs-kern:29676a

Signed-off-by: default avatarLachlan McIlroy <lachlan@sgi.com>
Signed-off-by: default avatarDavid Chinner <dgc@sgi.com>
Signed-off-by: default avatarTim Shimmin <tes@sgi.com>
parent 776a75fa

fs/xfs/xfs_buf_item.h

+5 −0
Original line number Diff line number Diff line
@@ -52,6 +52,11 @@ typedef struct xfs_buf_log_format_t { 
#define	XFS_BLI_UDQUOT_BUF	0x4

#define XFS_BLI_PDQUOT_BUF	0x8

#define	XFS_BLI_GDQUOT_BUF	0x10

/*

 * This flag indicates that the buffer contains newly allocated

 * inodes.

 */

#define	XFS_BLI_INODE_NEW_BUF	0x20



#define	XFS_BLI_CHUNK		128

#define	XFS_BLI_SHIFT		7

fs/xfs/xfs_log_recover.c

+48 −3
Original line number Diff line number Diff line
@@ -1874,6 +1874,7 @@ xlog_recover_do_inode_buffer( 
/*ARGSUSED*/

STATIC void

xlog_recover_do_reg_buffer(

	xfs_mount_t		*mp,

	xlog_recover_item_t	*item,

	xfs_buf_t		*bp,

	xfs_buf_log_format_t	*buf_f)
@@ -1884,6 +1885,50 @@ xlog_recover_do_reg_buffer( 
	unsigned int		*data_map = NULL;

	unsigned int		map_size = 0;

	int                     error;

	int			stale_buf = 1;



	/*

	 * Scan through the on-disk inode buffer and attempt to

	 * determine if it has been written to since it was logged.

	 *

	 * - If any of the magic numbers are incorrect then the buffer is stale

	 * - If any of the modes are non-zero then the buffer is not stale

	 * - If all of the modes are zero and at least one of the generation

	 *   counts is non-zero then the buffer is stale

	 *

	 * If the end result is a stale buffer then the log buffer is replayed

	 * otherwise it is skipped.

	 *

	 * This heuristic is not perfect.  It can be improved by scanning the

	 * entire inode chunk for evidence that any of the inode clusters have

	 * been updated.  To fix this problem completely we will need a major

	 * architectural change to the logging system.

	 */

	if (buf_f->blf_flags & XFS_BLI_INODE_NEW_BUF) {

		xfs_dinode_t    *dip;

		int             inodes_per_buf;

		int		mode_count = 0;

		int		gen_count = 0;



		stale_buf = 0;

		inodes_per_buf = XFS_BUF_COUNT(bp) >> mp->m_sb.sb_inodelog;

		for (i = 0; i < inodes_per_buf; i++) {

			dip = (xfs_dinode_t *)xfs_buf_offset(bp,

				i * mp->m_sb.sb_inodesize);

			if (be16_to_cpu(dip->di_core.di_magic) !=

					XFS_DINODE_MAGIC) {

				stale_buf = 1;

				break;

			}

			if (be16_to_cpu(dip->di_core.di_mode))

				mode_count++;

			if (be16_to_cpu(dip->di_core.di_gen))

				gen_count++;

		}



		if (!mode_count && gen_count)

			stale_buf = 1;

	}



	switch (buf_f->blf_type) {

	case XFS_LI_BUF:
@@ -1917,7 +1962,7 @@ xlog_recover_do_reg_buffer( 
					       -1, 0, XFS_QMOPT_DOWARN,

					       "dquot_buf_recover");

		}

		if (!error)

		if (!error && stale_buf)

			memcpy(xfs_buf_offset(bp,

				(uint)bit << XFS_BLI_SHIFT),	/* dest */

				item->ri_buf[i].i_addr,		/* source */
@@ -2089,7 +2134,7 @@ xlog_recover_do_dquot_buffer( 
	if (log->l_quotaoffs_flag & type)

		return;



	xlog_recover_do_reg_buffer(item, bp, buf_f);

	xlog_recover_do_reg_buffer(mp, item, bp, buf_f);

}



/*
@@ -2190,7 +2235,7 @@ xlog_recover_do_buffer_trans( 
		  (XFS_BLI_UDQUOT_BUF|XFS_BLI_PDQUOT_BUF|XFS_BLI_GDQUOT_BUF)) {

		xlog_recover_do_dquot_buffer(mp, log, item, bp, buf_f);

	} else {

		xlog_recover_do_reg_buffer(item, bp, buf_f);

		xlog_recover_do_reg_buffer(mp, item, bp, buf_f);

	}

	if (error)

		return XFS_ERROR(error);

fs/xfs/xfs_trans_buf.c

+1 −0
Original line number Diff line number Diff line
@@ -966,6 +966,7 @@ xfs_trans_inode_alloc_buf( 
	ASSERT(atomic_read(&bip->bli_refcount) > 0);



	bip->bli_flags |= XFS_BLI_INODE_ALLOC_BUF;

	bip->bli_format.blf_flags |= XFS_BLI_INODE_NEW_BUF;

}