aboutsummaryrefslogtreecommitdiffstats
path: root/fs/xfs/xfs_vfsops.c
diff options
context:
space:
mode:
authorDavid Chinner <dgc@sgi.com>2007-02-10 02:36:40 -0500
committerTim Shimmin <tes@sgi.com>2007-02-10 02:36:40 -0500
commit2823945fda94e0636be573a037c45cb7b6495af2 (patch)
treeb06f13e327978cb4e44710cec46839539c394cf5 /fs/xfs/xfs_vfsops.c
parent549054afadae44889c0b40d4c3bfb0207b98d5a0 (diff)
[XFS] Ensure a frozen filesystem has a clean log before writing the dummy
record. The current Linux XFS freeze code is a mess. We flush the metadata buffers out while we are still allowing new transactions to start and then fail to flush the dirty buffers back out before writing the unmount and dummy records to the log. This leads to problems when the frozen filesystem is used for snapshots - we do log recovery on a readonly image and often it appears that the log image in the snapshot is not correct. Hence we end up with hangs, oops and mount failures when trying to mount a snapshot image that has been created when the filesystem has not been correctly frozen. To fix this, we need to move th metadata flush to after we wait for all current transactions to complete in teh second stage of the freeze. This means that when we write the final log records, the log should be clean and recovery should never occur on a snapshot image created from a frozen filesystem. SGI-PV: 959267 SGI-Modid: xfs-linux-melb:xfs-kern:28010a Signed-off-by: David Chinner <dgc@sgi.com> Signed-off-by: Donald Douwsma <donaldd@sgi.com> Signed-off-by: Tim Shimmin <tes@sgi.com>
Diffstat (limited to 'fs/xfs/xfs_vfsops.c')
-rw-r--r--fs/xfs/xfs_vfsops.c26
1 files changed, 22 insertions, 4 deletions
diff --git a/fs/xfs/xfs_vfsops.c b/fs/xfs/xfs_vfsops.c
index f5ea74b999b6..c2a6eab7fa2d 100644
--- a/fs/xfs/xfs_vfsops.c
+++ b/fs/xfs/xfs_vfsops.c
@@ -872,6 +872,10 @@ xfs_statvfs(
872 * this by simply making sure the log gets flushed 872 * this by simply making sure the log gets flushed
873 * if SYNC_BDFLUSH is set, and by actually writing it 873 * if SYNC_BDFLUSH is set, and by actually writing it
874 * out otherwise. 874 * out otherwise.
875 * SYNC_DIO_WAIT - The caller wants us to wait for all direct I/Os
876 * as well to ensure all data I/O completes before we
877 * return. Forms the drain side of the write barrier needed
878 * to safely quiesce the filesystem.
875 * 879 *
876 */ 880 */
877/*ARGSUSED*/ 881/*ARGSUSED*/
@@ -883,10 +887,7 @@ xfs_sync(
883{ 887{
884 xfs_mount_t *mp = XFS_BHVTOM(bdp); 888 xfs_mount_t *mp = XFS_BHVTOM(bdp);
885 889
886 if (unlikely(flags == SYNC_QUIESCE)) 890 return xfs_syncsub(mp, flags, NULL);
887 return xfs_quiesce_fs(mp);
888 else
889 return xfs_syncsub(mp, flags, NULL);
890} 891}
891 892
892/* 893/*
@@ -1172,6 +1173,12 @@ xfs_sync_inodes(
1172 } 1173 }
1173 1174
1174 } 1175 }
1176 /*
1177 * When freezing, we need to wait ensure direct I/O is complete
1178 * as well to ensure all data modification is complete here
1179 */
1180 if (flags & SYNC_DIO_WAIT)
1181 vn_iowait(vp);
1175 1182
1176 if (flags & SYNC_BDFLUSH) { 1183 if (flags & SYNC_BDFLUSH) {
1177 if ((flags & SYNC_ATTR) && 1184 if ((flags & SYNC_ATTR) &&
@@ -1950,15 +1957,26 @@ xfs_showargs(
1950 return 0; 1957 return 0;
1951} 1958}
1952 1959
1960/*
1961 * Second stage of a freeze. The data is already frozen, now we have to take
1962 * care of the metadata. New transactions are already blocked, so we need to
1963 * wait for any remaining transactions to drain out before proceding.
1964 */
1953STATIC void 1965STATIC void
1954xfs_freeze( 1966xfs_freeze(
1955 bhv_desc_t *bdp) 1967 bhv_desc_t *bdp)
1956{ 1968{
1957 xfs_mount_t *mp = XFS_BHVTOM(bdp); 1969 xfs_mount_t *mp = XFS_BHVTOM(bdp);
1958 1970
1971 /* wait for all modifications to complete */
1959 while (atomic_read(&mp->m_active_trans) > 0) 1972 while (atomic_read(&mp->m_active_trans) > 0)
1960 delay(100); 1973 delay(100);
1961 1974
1975 /* flush inodes and push all remaining buffers out to disk */
1976 xfs_quiesce_fs(mp);
1977
1978 BUG_ON(atomic_read(&mp->m_active_trans) > 0);
1979
1962 /* Push the superblock and write an unmount record */ 1980 /* Push the superblock and write an unmount record */
1963 xfs_log_unmount_write(mp); 1981 xfs_log_unmount_write(mp);
1964 xfs_unmountfs_writesb(mp); 1982 xfs_unmountfs_writesb(mp);