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| author | Christoph Hellwig <hch@lst.de> | 2011-07-08 14:34:42 +0200 |
|---|---|---|
| committer | Christoph Hellwig <hch@lst.de> | 2011-07-08 14:34:42 +0200 |
| commit | 7a249cf83da1813cfa71cfe1e265b40045eceb47 (patch) | |
| tree | 0c665aad7d32614f7eaa5a11c1b534c8fb5037d3 /fs/xfs/xfs_mount.c | |
| parent | 33b8f7c2479dfcbc5c27174e44b5f659d9f33c70 (diff) | |
| download | linux-7a249cf83da1813cfa71cfe1e265b40045eceb47.tar.gz | |
xfs: fix filesystsem freeze race in xfs_trans_alloc
As pointed out by Jan xfs_trans_alloc can race with a concurrent filesystem freeze when it sleeps during the memory allocation. Fix this by moving the wait_for_freeze call after the memory allocation. This means moving the freeze into the low-level _xfs_trans_alloc helper, which thus grows a new argument. Also fix up some comments in that area while at it. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com> Reviewed-by: Dave Chinner <david@fromorbit.com>
Diffstat (limited to 'fs/xfs/xfs_mount.c')
| -rw-r--r-- | fs/xfs/xfs_mount.c | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c index b49b82363d20..63659ee316bd 100644 --- a/fs/xfs/xfs_mount.c +++ b/fs/xfs/xfs_mount.c @@ -1566,15 +1566,9 @@ xfs_fs_writable(xfs_mount_t *mp) } /* - * xfs_log_sbcount - * * Called either periodically to keep the on disk superblock values * roughly up to date or from unmount to make sure the values are * correct on a clean unmount. - * - * Note this code can be called during the process of freezing, so - * we may need to use the transaction allocator which does not not - * block when the transaction subsystem is in its frozen state. */ int xfs_log_sbcount( @@ -1596,7 +1590,13 @@ xfs_log_sbcount( if (!xfs_sb_version_haslazysbcount(&mp->m_sb)) return 0; - tp = _xfs_trans_alloc(mp, XFS_TRANS_SB_COUNT, KM_SLEEP); + /* + * We can be called during the process of freezing, so make sure + * we go ahead even if the frozen for new transactions. We will + * always use a sync transaction in the freeze path to make sure + * the transaction has completed by the time we return. + */ + tp = _xfs_trans_alloc(mp, XFS_TRANS_SB_COUNT, KM_SLEEP, false); error = xfs_trans_reserve(tp, 0, mp->m_sb.sb_sectsize + 128, 0, 0, XFS_DEFAULT_LOG_COUNT); if (error) { |