From e8e9ad42c1f1e1bfbe0e8c32c8cac02e9ebfb7ef Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Mon, 23 Feb 2015 21:45:32 +1100 Subject: [PATCH] xfs: take i_mmap_lock on extent manipulation operations Now we have the i_mmap_lock being held across the page fault IO path, we now add extent manipulation operation exclusion by adding the lock to the paths that directly modify extent maps. This includes truncate, hole punching and other fallocate based operations. The operations will now take both the i_iolock and the i_mmaplock in exclusive mode, thereby ensuring that all IO and page faults block without holding any page locks while the extent manipulation is in progress. This gives us the lock order during truncate of i_iolock -> i_mmaplock -> page_lock -> i_lock, hence providing the same lock order as the iolock provides the normal IO path without involving the mmap_sem. Signed-off-by: Dave Chinner Reviewed-by: Brian Foster Signed-off-by: Dave Chinner --- fs/xfs/xfs_file.c | 3 +++ fs/xfs/xfs_ioctl.c | 5 ++++- fs/xfs/xfs_iops.c | 7 ++++++- 3 files changed, 13 insertions(+), 2 deletions(-) diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index d55f011..609b5aa 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -841,6 +841,9 @@ xfs_file_fallocate( if (error) goto out_unlock; + xfs_ilock(ip, XFS_MMAPLOCK_EXCL); + iolock |= XFS_MMAPLOCK_EXCL; + if (mode & FALLOC_FL_PUNCH_HOLE) { error = xfs_free_file_space(ip, offset, len); if (error) diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c index ac4feae..4ee44dd 100644 --- a/fs/xfs/xfs_ioctl.c +++ b/fs/xfs/xfs_ioctl.c @@ -631,7 +631,7 @@ xfs_ioc_space( if (filp->f_flags & O_DSYNC) flags |= XFS_PREALLOC_SYNC; - if (ioflags & XFS_IO_INVIS) + if (ioflags & XFS_IO_INVIS) flags |= XFS_PREALLOC_INVISIBLE; error = mnt_want_write_file(filp); @@ -643,6 +643,9 @@ xfs_ioc_space( if (error) goto out_unlock; + xfs_ilock(ip, XFS_MMAPLOCK_EXCL); + iolock |= XFS_MMAPLOCK_EXCL; + switch (bf->l_whence) { case 0: /*SEEK_SET*/ break; diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c index d919ad7..7f59ad3 100644 --- a/fs/xfs/xfs_iops.c +++ b/fs/xfs/xfs_iops.c @@ -765,6 +765,7 @@ xfs_setattr_size( return error; ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL)); + ASSERT(xfs_isilocked(ip, XFS_MMAPLOCK_EXCL)); ASSERT(S_ISREG(ip->i_d.di_mode)); ASSERT((iattr->ia_valid & (ATTR_UID|ATTR_GID|ATTR_ATIME|ATTR_ATIME_SET| ATTR_MTIME_SET|ATTR_KILL_PRIV|ATTR_TIMES_SET)) == 0); @@ -984,8 +985,12 @@ xfs_vn_setattr( xfs_ilock(ip, iolock); error = xfs_break_layouts(dentry->d_inode, &iolock); - if (!error) + if (!error) { + xfs_ilock(ip, XFS_MMAPLOCK_EXCL); + iolock |= XFS_MMAPLOCK_EXCL; + error = xfs_setattr_size(ip, iattr); + } xfs_iunlock(ip, iolock); } else { error = xfs_setattr_nonsize(ip, iattr, 0); -- 2.7.4