From 1c2ed3952e66315720f5753fe57465d9426ef332 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 commit e8e9ad42c1f1e1bfbe0e8c32c8cac02e9ebfb7ef upstream. 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 [bwh: Backported to 3.16: - We never need to break layouts, so take both i_iolock and i_mmaplock at the same time - Adjust context] Signed-off-by: Ben Hutchings Cc: Jan Kara Cc: xfs@oss.sgi.com --- fs/xfs/xfs_file.c | 4 ++-- fs/xfs/xfs_ioctl.c | 4 ++-- fs/xfs/xfs_iops.c | 5 +++-- 3 files changed, 7 insertions(+), 6 deletions(-) diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index e9ae58e33c6c..975aaac7494e 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -786,7 +786,7 @@ xfs_file_fallocate( FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE)) return -EOPNOTSUPP; - xfs_ilock(ip, XFS_IOLOCK_EXCL); + xfs_ilock(ip, XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL); if (mode & FALLOC_FL_PUNCH_HOLE) { error = xfs_free_file_space(ip, offset, len); if (error) @@ -866,7 +866,7 @@ xfs_file_fallocate( } out_unlock: - xfs_iunlock(ip, XFS_IOLOCK_EXCL); + xfs_iunlock(ip, XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL); return -error; } diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c index 8bc1bbce7451..afc859f44d01 100644 --- a/fs/xfs/xfs_ioctl.c +++ b/fs/xfs/xfs_ioctl.c @@ -640,7 +640,7 @@ xfs_ioc_space( if (error) return error; - xfs_ilock(ip, XFS_IOLOCK_EXCL); + xfs_ilock(ip, XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL); switch (bf->l_whence) { case 0: /*SEEK_SET*/ @@ -757,7 +757,7 @@ xfs_ioc_space( error = xfs_trans_commit(tp, 0); out_unlock: - xfs_iunlock(ip, XFS_IOLOCK_EXCL); + xfs_iunlock(ip, XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL); mnt_drop_write_file(filp); return -error; } diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c index 537d8daeaa9e..1d392bbb2c9f 100644 --- a/fs/xfs/xfs_iops.c +++ b/fs/xfs/xfs_iops.c @@ -759,6 +759,7 @@ xfs_setattr_size( return XFS_ERROR(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); @@ -935,9 +936,9 @@ xfs_vn_setattr( int error; if (iattr->ia_valid & ATTR_SIZE) { - xfs_ilock(ip, XFS_IOLOCK_EXCL); + xfs_ilock(ip, XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL); error = xfs_setattr_size(ip, iattr); - xfs_iunlock(ip, XFS_IOLOCK_EXCL); + xfs_iunlock(ip, XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL); } else { error = xfs_setattr_nonsize(ip, iattr, 0); }