From 40095b64f5da601a8ab61fbe4b40feb46830052e Mon Sep 17 00:00:00 2001 From: David Chinner Date: Mon, 14 May 2007 18:24:09 +1000 Subject: [PATCH] [XFS] Sleeping with the ilock waiting for I/O completion is Bad. Recent fixes to the filesystem freezing code introduced a vn_iowait call in the middle of the sync code. Unfortunately, at the point where this call was added we are holding the ilock. The ilock is needed by I/O completion for unwritten extent conversion and now updating the file size. Hence I/o cannot complete if we hold the ilock while waiting for I/O completion. Fix up the bug and clean the code up around it. SGI-PV: 963674 SGI-Modid: xfs-linux-melb:xfs-kern:28566a Signed-off-by: David Chinner Signed-off-by: Christoph Hellwig Signed-off-by: Tim Shimmin --- fs/xfs/xfs_vfsops.c | 73 +++++++++++++++++---------------------------- 1 file changed, 28 insertions(+), 45 deletions(-) diff --git a/fs/xfs/xfs_vfsops.c b/fs/xfs/xfs_vfsops.c index 65c561201c..92c1425d06 100644 --- a/fs/xfs/xfs_vfsops.c +++ b/fs/xfs/xfs_vfsops.c @@ -1128,58 +1128,41 @@ xfs_sync_inodes( * in the inode list. */ - if ((flags & SYNC_CLOSE) && (vp != NULL)) { - /* - * This is the shutdown case. We just need to - * flush and invalidate all the pages associated - * with the inode. Drop the inode lock since - * we can't hold it across calls to the buffer - * cache. - * - * We don't set the VREMAPPING bit in the vnode - * here, because we don't hold the vnode lock - * exclusively. It doesn't really matter, though, - * because we only come here when we're shutting - * down anyway. - */ - xfs_iunlock(ip, XFS_ILOCK_SHARED); - - if (XFS_FORCED_SHUTDOWN(mp)) { - bhv_vop_toss_pages(vp, 0, -1, FI_REMAPF); - } else { - error = bhv_vop_flushinval_pages(vp, 0, -1, FI_REMAPF); + /* + * If we have to flush data or wait for I/O completion + * we need to drop the ilock that we currently hold. + * If we need to drop the lock, insert a marker if we + * have not already done so. + */ + if ((flags & (SYNC_CLOSE|SYNC_IOWAIT)) || + ((flags & SYNC_DELWRI) && VN_DIRTY(vp))) { + if (mount_locked) { + IPOINTER_INSERT(ip, mp); } + xfs_iunlock(ip, XFS_ILOCK_SHARED); - xfs_ilock(ip, XFS_ILOCK_SHARED); - - } else if ((flags & SYNC_DELWRI) && (vp != NULL)) { - if (VN_DIRTY(vp)) { - /* We need to have dropped the lock here, - * so insert a marker if we have not already - * done so. - */ - if (mount_locked) { - IPOINTER_INSERT(ip, mp); - } - - /* - * Drop the inode lock since we can't hold it - * across calls to the buffer cache. - */ - xfs_iunlock(ip, XFS_ILOCK_SHARED); + if (flags & SYNC_CLOSE) { + /* Shutdown case. Flush and invalidate. */ + if (XFS_FORCED_SHUTDOWN(mp)) + bhv_vop_toss_pages(vp, 0, -1, FI_REMAPF); + else + error = bhv_vop_flushinval_pages(vp, 0, + -1, FI_REMAPF); + } else if ((flags & SYNC_DELWRI) && VN_DIRTY(vp)) { error = bhv_vop_flush_pages(vp, (xfs_off_t)0, -1, fflag, FI_NONE); - xfs_ilock(ip, XFS_ILOCK_SHARED); } + /* + * When freezing, we need to wait ensure all I/O (including direct + * I/O) is complete to ensure no further data modification can take + * place after this point + */ + if (flags & SYNC_IOWAIT) + vn_iowait(vp); + + xfs_ilock(ip, XFS_ILOCK_SHARED); } - /* - * When freezing, we need to wait ensure all I/O (including direct - * I/O) is complete to ensure no further data modification can take - * place after this point - */ - if (flags & SYNC_IOWAIT) - vn_iowait(vp); if (flags & SYNC_BDFLUSH) { if ((flags & SYNC_ATTR) && -- 2.39.5