From 71dfd5a396d11512aa6c8ed0d35b268bc084bb9b Mon Sep 17 00:00:00 2001 From: Lachlan McIlroy Date: Tue, 8 May 2007 13:50:12 +1000 Subject: [PATCH] [XFS] Fix race in xfs_write() b/w dmapi callout and direct I/O checks. In xfs_write() the iolock is dropped and reacquired in XFS_SEND_DATA() which means that the file could change from not-cached to cached and we need to redo the direct I/O checks. We should also redo the direct I/O checks when the file size changes regardless if O_APPEND is set or not. SGI-PV: 963483 SGI-Modid: xfs-linux-melb:xfs-kern:28440a Signed-off-by: Lachlan McIlroy Signed-off-by: David Chinner Signed-off-by: Tim Shimmin --- fs/xfs/linux-2.6/xfs_lrw.c | 53 +++++++++++++++++++------------------- 1 file changed, 26 insertions(+), 27 deletions(-) diff --git a/fs/xfs/linux-2.6/xfs_lrw.c b/fs/xfs/linux-2.6/xfs_lrw.c index 82ab792c7fc..b2a1beb3388 100644 --- a/fs/xfs/linux-2.6/xfs_lrw.c +++ b/fs/xfs/linux-2.6/xfs_lrw.c @@ -724,34 +724,8 @@ start: goto out_unlock_mutex; } - if (ioflags & IO_ISDIRECT) { - xfs_buftarg_t *target = - (xip->i_d.di_flags & XFS_DIFLAG_REALTIME) ? - mp->m_rtdev_targp : mp->m_ddev_targp; - - if ((pos & target->bt_smask) || (count & target->bt_smask)) { - xfs_iunlock(xip, XFS_ILOCK_EXCL|iolock); - return XFS_ERROR(-EINVAL); - } - - if (!need_i_mutex && (VN_CACHED(vp) || pos > xip->i_size)) { - xfs_iunlock(xip, XFS_ILOCK_EXCL|iolock); - iolock = XFS_IOLOCK_EXCL; - locktype = VRWLOCK_WRITE; - need_i_mutex = 1; - mutex_lock(&inode->i_mutex); - xfs_ilock(xip, XFS_ILOCK_EXCL|iolock); - goto start; - } - } - - new_size = pos + count; - if (new_size > xip->i_size) - io->io_new_size = new_size; - if ((DM_EVENT_ENABLED(vp->v_vfsp, xip, DM_EVENT_WRITE) && !(ioflags & IO_INVIS) && !eventsent)) { - loff_t savedsize = pos; int dmflags = FILP_DELAY_FLAG(file); if (need_i_mutex) @@ -774,10 +748,35 @@ start: * event prevents another call to XFS_SEND_DATA, which is * what allows the size to change in the first place. */ - if ((file->f_flags & O_APPEND) && savedsize != xip->i_size) + if ((file->f_flags & O_APPEND) && pos != xip->i_size) goto start; } + if (ioflags & IO_ISDIRECT) { + xfs_buftarg_t *target = + (xip->i_d.di_flags & XFS_DIFLAG_REALTIME) ? + mp->m_rtdev_targp : mp->m_ddev_targp; + + if ((pos & target->bt_smask) || (count & target->bt_smask)) { + xfs_iunlock(xip, XFS_ILOCK_EXCL|iolock); + return XFS_ERROR(-EINVAL); + } + + if (!need_i_mutex && (VN_CACHED(vp) || pos > xip->i_size)) { + xfs_iunlock(xip, XFS_ILOCK_EXCL|iolock); + iolock = XFS_IOLOCK_EXCL; + locktype = VRWLOCK_WRITE; + need_i_mutex = 1; + mutex_lock(&inode->i_mutex); + xfs_ilock(xip, XFS_ILOCK_EXCL|iolock); + goto start; + } + } + + new_size = pos + count; + if (new_size > xip->i_size) + io->io_new_size = new_size; + if (likely(!(ioflags & IO_INVIS))) { file_update_time(file); xfs_ichgtime_fast(xip, inode, -- 2.20.1