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Commit 516b2e7c authored by David Chinner's avatar David Chinner Committed by Tim Shimmin
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[XFS] Fix remount,readonly path to flush everything correctly. 



The remount readonly path can fail to writeback properly because we still
have active transactions after calling xfs_quiesce_fs(). Further
investigation shows that this path is broken in the same ways that the xfs
freeze path was broken so fix it the same way.

SGI-PV: 964464
SGI-Modid: xfs-linux-melb:xfs-kern:28869a

Signed-off-by: default avatarDavid Chinner <dgc@sgi.com>
Signed-off-by: default avatarChristoph Hellwig <hch@infradead.org>
Signed-off-by: default avatarTim Shimmin <tes@sgi.com>
parent 957d0ebe

fs/xfs/linux-2.6/xfs_super.c

+1 −1
Original line number Diff line number Diff line
@@ -664,7 +664,7 @@ xfs_fs_sync_super( 
		 * occur here so don't bother flushing the buftarg (i.e

		 * SYNC_QUIESCE) because it'll just get dirty again.

		 */

		flags = SYNC_FSDATA | SYNC_DELWRI | SYNC_WAIT | SYNC_IOWAIT;

		flags = SYNC_DATA_QUIESCE;

	} else

		flags = SYNC_FSDATA | (wait ? SYNC_WAIT : 0);

fs/xfs/linux-2.6/xfs_vfs.h

+14 −0
Original line number Diff line number Diff line
@@ -94,6 +94,20 @@ typedef enum { 
#define SYNC_IOWAIT		0x0100  /* wait for all I/O to complete */

#define SYNC_SUPER		0x0200  /* flush superblock to disk */



/*

 * When remounting a filesystem read-only or freezing the filesystem,

 * we have two phases to execute. This first phase is syncing the data

 * before we quiesce the fielsystem, and the second is flushing all the

 * inodes out after we've waited for all the transactions created by

 * the first phase to complete. The second phase uses SYNC_INODE_QUIESCE

 * to ensure that the inodes are written to their location on disk

 * rather than just existing in transactions in the log. This means

 * after a quiesce there is no log replay required to write the inodes

 * to disk (this is the main difference between a sync and a quiesce).

 */

#define SYNC_DATA_QUIESCE	(SYNC_DELWRI|SYNC_FSDATA|SYNC_WAIT|SYNC_IOWAIT)

#define SYNC_INODE_QUIESCE	(SYNC_REMOUNT|SYNC_ATTR|SYNC_WAIT)



#define SHUTDOWN_META_IO_ERROR	0x0001	/* write attempt to metadata failed */

#define SHUTDOWN_LOG_IO_ERROR	0x0002	/* write attempt to the log failed */

#define SHUTDOWN_FORCE_UMOUNT	0x0004	/* shutdown from a forced unmount */

fs/xfs/xfs_vfsops.c

+31 −22
Original line number Diff line number Diff line
@@ -640,7 +640,7 @@ xfs_quiesce_fs( 
	 * we can write the unmount record.

	 */

	do {

		xfs_syncsub(mp, SYNC_REMOUNT|SYNC_ATTR|SYNC_WAIT, NULL);

		xfs_syncsub(mp, SYNC_INODE_QUIESCE, NULL);

		pincount = xfs_flush_buftarg(mp->m_ddev_targp, 1);

		if (!pincount) {

			delay(50);
@@ -651,6 +651,30 @@ xfs_quiesce_fs( 
	return 0;

}



/*

 * Second stage of a quiesce. The data is already synced, now we have to take

 * care of the metadata. New transactions are already blocked, so we need to

 * wait for any remaining transactions to drain out before proceding.

 */

STATIC void

xfs_attr_quiesce(

	xfs_mount_t	*mp)

{

	/* wait for all modifications to complete */

	while (atomic_read(&mp->m_active_trans) > 0)

		delay(100);



	/* flush inodes and push all remaining buffers out to disk */

	xfs_quiesce_fs(mp);



	ASSERT_ALWAYS(atomic_read(&mp->m_active_trans) == 0);



	/* Push the superblock and write an unmount record */

	xfs_log_sbcount(mp, 1);

	xfs_log_unmount_write(mp);

	xfs_unmountfs_writesb(mp);

}



STATIC int

xfs_mntupdate(

	bhv_desc_t			*bdp,
@@ -670,11 +694,8 @@ xfs_mntupdate( 
			mp->m_flags &= ~XFS_MOUNT_BARRIER;

		}

	} else if (!(vfsp->vfs_flag & VFS_RDONLY)) {	/* rw -> ro */

		bhv_vfs_sync(vfsp, SYNC_FSDATA|SYNC_BDFLUSH|SYNC_ATTR, NULL);

		xfs_quiesce_fs(mp);

		xfs_log_sbcount(mp, 1);

		xfs_log_unmount_write(mp);

		xfs_unmountfs_writesb(mp);

		bhv_vfs_sync(vfsp, SYNC_DATA_QUIESCE, NULL);

		xfs_attr_quiesce(mp);

		vfsp->vfs_flag |= VFS_RDONLY;

	}

	return 0;
@@ -1952,9 +1973,9 @@ xfs_showargs( 
}



/*

 * Second stage of a freeze. The data is already frozen, now we have to take

 * care of the metadata. New transactions are already blocked, so we need to

 * wait for any remaining transactions to drain out before proceding.

 * Second stage of a freeze. The data is already frozen so we only

 * need to take care of themetadata. Once that's done write a dummy

 * record to dirty the log in case of a crash while frozen.

 */

STATIC void

xfs_freeze(
@@ -1962,19 +1983,7 @@ xfs_freeze( 
{

	xfs_mount_t	*mp = XFS_BHVTOM(bdp);



	/* wait for all modifications to complete */

	while (atomic_read(&mp->m_active_trans) > 0)

		delay(100);



	/* flush inodes and push all remaining buffers out to disk */

	xfs_quiesce_fs(mp);



	ASSERT_ALWAYS(atomic_read(&mp->m_active_trans) == 0);



	/* Push the superblock and write an unmount record */

	xfs_log_sbcount(mp, 1);

	xfs_log_unmount_write(mp);

	xfs_unmountfs_writesb(mp);

	xfs_attr_quiesce(mp);

	xfs_fs_log_dummy(mp);

}