Message ID | 20210607145236.31852-9-jack@suse.cz |
---|---|
State | New |
Headers | show |
Series | fs: Hole punch vs page cache filling races | expand |
On Mon, Jun 07, 2021 at 04:52:19PM +0200, Jan Kara wrote: > Convert places in XFS that take MMAPLOCK for two inodes to use helper > VFS provides for it (filemap_invalidate_down_write_two()). Note that > this changes lock ordering for MMAPLOCK from inode number based ordering > to pointer based ordering VFS generally uses. > > CC: "Darrick J. Wong" <djwong@kernel.org> > Reviewed-by: Darrick J. Wong <djwong@kernel.org> > Signed-off-by: Jan Kara <jack@suse.cz> Looks straightforward, Reviewed-by: Darrick J. Wong <djwong@kernel.org> --D > --- > fs/xfs/xfs_bmap_util.c | 15 ++++++++------- > fs/xfs/xfs_inode.c | 37 +++++++++++-------------------------- > 2 files changed, 19 insertions(+), 33 deletions(-) > > diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c > index a5e9d7d34023..7421d6ec4def 100644 > --- a/fs/xfs/xfs_bmap_util.c > +++ b/fs/xfs/xfs_bmap_util.c > @@ -1582,7 +1582,6 @@ xfs_swap_extents( > struct xfs_bstat *sbp = &sxp->sx_stat; > int src_log_flags, target_log_flags; > int error = 0; > - int lock_flags; > uint64_t f; > int resblks = 0; > unsigned int flags = 0; > @@ -1594,8 +1593,8 @@ xfs_swap_extents( > * do the rest of the checks. > */ > lock_two_nondirectories(VFS_I(ip), VFS_I(tip)); > - lock_flags = XFS_MMAPLOCK_EXCL; > - xfs_lock_two_inodes(ip, XFS_MMAPLOCK_EXCL, tip, XFS_MMAPLOCK_EXCL); > + filemap_invalidate_lock_two(VFS_I(ip)->i_mapping, > + VFS_I(tip)->i_mapping); > > /* Verify that both files have the same format */ > if ((VFS_I(ip)->i_mode & S_IFMT) != (VFS_I(tip)->i_mode & S_IFMT)) { > @@ -1667,7 +1666,6 @@ xfs_swap_extents( > * or cancel will unlock the inodes from this point onwards. > */ > xfs_lock_two_inodes(ip, XFS_ILOCK_EXCL, tip, XFS_ILOCK_EXCL); > - lock_flags |= XFS_ILOCK_EXCL; > xfs_trans_ijoin(tp, ip, 0); > xfs_trans_ijoin(tp, tip, 0); > > @@ -1786,13 +1784,16 @@ xfs_swap_extents( > trace_xfs_swap_extent_after(ip, 0); > trace_xfs_swap_extent_after(tip, 1); > > +out_unlock_ilock: > + xfs_iunlock(ip, XFS_ILOCK_EXCL); > + xfs_iunlock(tip, XFS_ILOCK_EXCL); > out_unlock: > - xfs_iunlock(ip, lock_flags); > - xfs_iunlock(tip, lock_flags); > + filemap_invalidate_unlock_two(VFS_I(ip)->i_mapping, > + VFS_I(tip)->i_mapping); > unlock_two_nondirectories(VFS_I(ip), VFS_I(tip)); > return error; > > out_trans_cancel: > xfs_trans_cancel(tp); > - goto out_unlock; > + goto out_unlock_ilock; > } > diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c > index e1854a660809..0468f56f3bbb 100644 > --- a/fs/xfs/xfs_inode.c > +++ b/fs/xfs/xfs_inode.c > @@ -556,12 +556,10 @@ xfs_lock_inodes( > } > > /* > - * xfs_lock_two_inodes() can only be used to lock one type of lock at a time - > - * the mmaplock or the ilock, but not more than one type at a time. If we lock > - * more than one at a time, lockdep will report false positives saying we have > - * violated locking orders. The iolock must be double-locked separately since > - * we use i_rwsem for that. We now support taking one lock EXCL and the other > - * SHARED. > + * xfs_lock_two_inodes() can only be used to lock ilock. The iolock and > + * mmaplock must be double-locked separately since we use i_rwsem and > + * invalidate_lock for that. We now support taking one lock EXCL and the > + * other SHARED. > */ > void > xfs_lock_two_inodes( > @@ -579,15 +577,8 @@ xfs_lock_two_inodes( > ASSERT(hweight32(ip1_mode) == 1); > ASSERT(!(ip0_mode & (XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL))); > ASSERT(!(ip1_mode & (XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL))); > - ASSERT(!(ip0_mode & (XFS_MMAPLOCK_SHARED|XFS_MMAPLOCK_EXCL)) || > - !(ip0_mode & (XFS_ILOCK_SHARED|XFS_ILOCK_EXCL))); > - ASSERT(!(ip1_mode & (XFS_MMAPLOCK_SHARED|XFS_MMAPLOCK_EXCL)) || > - !(ip1_mode & (XFS_ILOCK_SHARED|XFS_ILOCK_EXCL))); > - ASSERT(!(ip1_mode & (XFS_MMAPLOCK_SHARED|XFS_MMAPLOCK_EXCL)) || > - !(ip0_mode & (XFS_ILOCK_SHARED|XFS_ILOCK_EXCL))); > - ASSERT(!(ip0_mode & (XFS_MMAPLOCK_SHARED|XFS_MMAPLOCK_EXCL)) || > - !(ip1_mode & (XFS_ILOCK_SHARED|XFS_ILOCK_EXCL))); > - > + ASSERT(!(ip0_mode & (XFS_MMAPLOCK_SHARED|XFS_MMAPLOCK_EXCL))); > + ASSERT(!(ip1_mode & (XFS_MMAPLOCK_SHARED|XFS_MMAPLOCK_EXCL))); > ASSERT(ip0->i_ino != ip1->i_ino); > > if (ip0->i_ino > ip1->i_ino) { > @@ -3750,11 +3741,8 @@ xfs_ilock2_io_mmap( > ret = xfs_iolock_two_inodes_and_break_layout(VFS_I(ip1), VFS_I(ip2)); > if (ret) > return ret; > - if (ip1 == ip2) > - xfs_ilock(ip1, XFS_MMAPLOCK_EXCL); > - else > - xfs_lock_two_inodes(ip1, XFS_MMAPLOCK_EXCL, > - ip2, XFS_MMAPLOCK_EXCL); > + filemap_invalidate_lock_two(VFS_I(ip1)->i_mapping, > + VFS_I(ip2)->i_mapping); > return 0; > } > > @@ -3764,12 +3752,9 @@ xfs_iunlock2_io_mmap( > struct xfs_inode *ip1, > struct xfs_inode *ip2) > { > - bool same_inode = (ip1 == ip2); > - > - xfs_iunlock(ip2, XFS_MMAPLOCK_EXCL); > - if (!same_inode) > - xfs_iunlock(ip1, XFS_MMAPLOCK_EXCL); > + filemap_invalidate_unlock_two(VFS_I(ip1)->i_mapping, > + VFS_I(ip2)->i_mapping); > inode_unlock(VFS_I(ip2)); > - if (!same_inode) > + if (ip1 != ip2) > inode_unlock(VFS_I(ip1)); > } > -- > 2.26.2 >
diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c index a5e9d7d34023..7421d6ec4def 100644 --- a/fs/xfs/xfs_bmap_util.c +++ b/fs/xfs/xfs_bmap_util.c @@ -1582,7 +1582,6 @@ xfs_swap_extents( struct xfs_bstat *sbp = &sxp->sx_stat; int src_log_flags, target_log_flags; int error = 0; - int lock_flags; uint64_t f; int resblks = 0; unsigned int flags = 0; @@ -1594,8 +1593,8 @@ xfs_swap_extents( * do the rest of the checks. */ lock_two_nondirectories(VFS_I(ip), VFS_I(tip)); - lock_flags = XFS_MMAPLOCK_EXCL; - xfs_lock_two_inodes(ip, XFS_MMAPLOCK_EXCL, tip, XFS_MMAPLOCK_EXCL); + filemap_invalidate_lock_two(VFS_I(ip)->i_mapping, + VFS_I(tip)->i_mapping); /* Verify that both files have the same format */ if ((VFS_I(ip)->i_mode & S_IFMT) != (VFS_I(tip)->i_mode & S_IFMT)) { @@ -1667,7 +1666,6 @@ xfs_swap_extents( * or cancel will unlock the inodes from this point onwards. */ xfs_lock_two_inodes(ip, XFS_ILOCK_EXCL, tip, XFS_ILOCK_EXCL); - lock_flags |= XFS_ILOCK_EXCL; xfs_trans_ijoin(tp, ip, 0); xfs_trans_ijoin(tp, tip, 0); @@ -1786,13 +1784,16 @@ xfs_swap_extents( trace_xfs_swap_extent_after(ip, 0); trace_xfs_swap_extent_after(tip, 1); +out_unlock_ilock: + xfs_iunlock(ip, XFS_ILOCK_EXCL); + xfs_iunlock(tip, XFS_ILOCK_EXCL); out_unlock: - xfs_iunlock(ip, lock_flags); - xfs_iunlock(tip, lock_flags); + filemap_invalidate_unlock_two(VFS_I(ip)->i_mapping, + VFS_I(tip)->i_mapping); unlock_two_nondirectories(VFS_I(ip), VFS_I(tip)); return error; out_trans_cancel: xfs_trans_cancel(tp); - goto out_unlock; + goto out_unlock_ilock; } diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c index e1854a660809..0468f56f3bbb 100644 --- a/fs/xfs/xfs_inode.c +++ b/fs/xfs/xfs_inode.c @@ -556,12 +556,10 @@ xfs_lock_inodes( } /* - * xfs_lock_two_inodes() can only be used to lock one type of lock at a time - - * the mmaplock or the ilock, but not more than one type at a time. If we lock - * more than one at a time, lockdep will report false positives saying we have - * violated locking orders. The iolock must be double-locked separately since - * we use i_rwsem for that. We now support taking one lock EXCL and the other - * SHARED. + * xfs_lock_two_inodes() can only be used to lock ilock. The iolock and + * mmaplock must be double-locked separately since we use i_rwsem and + * invalidate_lock for that. We now support taking one lock EXCL and the + * other SHARED. */ void xfs_lock_two_inodes( @@ -579,15 +577,8 @@ xfs_lock_two_inodes( ASSERT(hweight32(ip1_mode) == 1); ASSERT(!(ip0_mode & (XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL))); ASSERT(!(ip1_mode & (XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL))); - ASSERT(!(ip0_mode & (XFS_MMAPLOCK_SHARED|XFS_MMAPLOCK_EXCL)) || - !(ip0_mode & (XFS_ILOCK_SHARED|XFS_ILOCK_EXCL))); - ASSERT(!(ip1_mode & (XFS_MMAPLOCK_SHARED|XFS_MMAPLOCK_EXCL)) || - !(ip1_mode & (XFS_ILOCK_SHARED|XFS_ILOCK_EXCL))); - ASSERT(!(ip1_mode & (XFS_MMAPLOCK_SHARED|XFS_MMAPLOCK_EXCL)) || - !(ip0_mode & (XFS_ILOCK_SHARED|XFS_ILOCK_EXCL))); - ASSERT(!(ip0_mode & (XFS_MMAPLOCK_SHARED|XFS_MMAPLOCK_EXCL)) || - !(ip1_mode & (XFS_ILOCK_SHARED|XFS_ILOCK_EXCL))); - + ASSERT(!(ip0_mode & (XFS_MMAPLOCK_SHARED|XFS_MMAPLOCK_EXCL))); + ASSERT(!(ip1_mode & (XFS_MMAPLOCK_SHARED|XFS_MMAPLOCK_EXCL))); ASSERT(ip0->i_ino != ip1->i_ino); if (ip0->i_ino > ip1->i_ino) { @@ -3750,11 +3741,8 @@ xfs_ilock2_io_mmap( ret = xfs_iolock_two_inodes_and_break_layout(VFS_I(ip1), VFS_I(ip2)); if (ret) return ret; - if (ip1 == ip2) - xfs_ilock(ip1, XFS_MMAPLOCK_EXCL); - else - xfs_lock_two_inodes(ip1, XFS_MMAPLOCK_EXCL, - ip2, XFS_MMAPLOCK_EXCL); + filemap_invalidate_lock_two(VFS_I(ip1)->i_mapping, + VFS_I(ip2)->i_mapping); return 0; } @@ -3764,12 +3752,9 @@ xfs_iunlock2_io_mmap( struct xfs_inode *ip1, struct xfs_inode *ip2) { - bool same_inode = (ip1 == ip2); - - xfs_iunlock(ip2, XFS_MMAPLOCK_EXCL); - if (!same_inode) - xfs_iunlock(ip1, XFS_MMAPLOCK_EXCL); + filemap_invalidate_unlock_two(VFS_I(ip1)->i_mapping, + VFS_I(ip2)->i_mapping); inode_unlock(VFS_I(ip2)); - if (!same_inode) + if (ip1 != ip2) inode_unlock(VFS_I(ip1)); }