From e31cbde7ecdcfdf22eac6fd37e63548adacc4ede Mon Sep 17 00:00:00 2001 From: Pavel Reichl Date: Fri, 16 Oct 2020 04:10:02 +0200 Subject: xfs: Refactor xfs_isilocked() Introduce a new __xfs_rwsem_islocked predicate to encapsulate checking the state of a rw_semaphore, then refactor xfs_isilocked to use it. Signed-off-by: Pavel Reichl Suggested-by: Dave Chinner Suggested-by: Eric Sandeen Suggested-by: Darrick J. Wong Reviewed-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Jan Kara --- fs/xfs/xfs_inode.c | 34 ++++++++++++++++++++++++++-------- 1 file changed, 26 insertions(+), 8 deletions(-) (limited to 'fs/xfs/xfs_inode.c') diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c index a835ceb79ba5..359e2cd44ad7 100644 --- a/fs/xfs/xfs_inode.c +++ b/fs/xfs/xfs_inode.c @@ -343,9 +343,29 @@ xfs_ilock_demote( } #if defined(DEBUG) || defined(XFS_WARN) -int +static inline bool +__xfs_rwsem_islocked( + struct rw_semaphore *rwsem, + bool shared) +{ + if (!debug_locks) + return rwsem_is_locked(rwsem); + + if (!shared) + return lockdep_is_held_type(rwsem, 0); + + /* + * We are checking that the lock is held at least in shared + * mode but don't care that it might be held exclusively + * (i.e. shared | excl). Hence we check if the lock is held + * in any mode rather than an explicit shared mode. + */ + return lockdep_is_held_type(rwsem, -1); +} + +bool xfs_isilocked( - xfs_inode_t *ip, + struct xfs_inode *ip, uint lock_flags) { if (lock_flags & (XFS_ILOCK_EXCL|XFS_ILOCK_SHARED)) { @@ -360,15 +380,13 @@ xfs_isilocked( return rwsem_is_locked(&ip->i_mmaplock.mr_lock); } - if (lock_flags & (XFS_IOLOCK_EXCL|XFS_IOLOCK_SHARED)) { - if (!(lock_flags & XFS_IOLOCK_SHARED)) - return !debug_locks || - lockdep_is_held_type(&VFS_I(ip)->i_rwsem, 0); - return rwsem_is_locked(&VFS_I(ip)->i_rwsem); + if (lock_flags & (XFS_IOLOCK_EXCL | XFS_IOLOCK_SHARED)) { + return __xfs_rwsem_islocked(&VFS_I(ip)->i_rwsem, + (lock_flags & XFS_IOLOCK_SHARED)); } ASSERT(0); - return 0; + return false; } #endif -- cgit v1.2.3 From 2433480a7e1d0c057442b284c336cfaa61523117 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Mon, 12 Apr 2021 18:56:24 +0200 Subject: xfs: Convert to use invalidate_lock Use invalidate_lock instead of XFS internal i_mmap_lock. The intended purpose of invalidate_lock is exactly the same. Note that the locking in __xfs_filemap_fault() slightly changes as filemap_fault() already takes invalidate_lock. Reviewed-by: Christoph Hellwig Reviewed-by: Darrick J. Wong CC: CC: "Darrick J. Wong" Signed-off-by: Jan Kara --- fs/xfs/xfs_file.c | 13 ++++++++----- fs/xfs/xfs_inode.c | 50 ++++++++++++++++++++++++++------------------------ fs/xfs/xfs_inode.h | 1 - fs/xfs/xfs_super.c | 2 -- 4 files changed, 34 insertions(+), 32 deletions(-) (limited to 'fs/xfs/xfs_inode.c') diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index cc3cfb12df53..3dfbdcdb0d1c 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -1302,7 +1302,7 @@ xfs_file_llseek( * * mmap_lock (MM) * sb_start_pagefault(vfs, freeze) - * i_mmaplock (XFS - truncate serialisation) + * invalidate_lock (vfs/XFS_MMAPLOCK - truncate serialisation) * page_lock (MM) * i_lock (XFS - extent map serialisation) */ @@ -1323,24 +1323,27 @@ __xfs_filemap_fault( file_update_time(vmf->vma->vm_file); } - xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED); if (IS_DAX(inode)) { pfn_t pfn; + xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED); ret = dax_iomap_fault(vmf, pe_size, &pfn, NULL, (write_fault && !vmf->cow_page) ? &xfs_direct_write_iomap_ops : &xfs_read_iomap_ops); if (ret & VM_FAULT_NEEDDSYNC) ret = dax_finish_sync_fault(vmf, pe_size, pfn); + xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED); } else { - if (write_fault) + if (write_fault) { + xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED); ret = iomap_page_mkwrite(vmf, &xfs_buffered_write_iomap_ops); - else + xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED); + } else { ret = filemap_fault(vmf); + } } - xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED); if (write_fault) sb_end_pagefault(inode->i_sb); diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c index 359e2cd44ad7..d6a8ac76b45d 100644 --- a/fs/xfs/xfs_inode.c +++ b/fs/xfs/xfs_inode.c @@ -132,7 +132,7 @@ xfs_ilock_attr_map_shared( /* * In addition to i_rwsem in the VFS inode, the xfs inode contains 2 - * multi-reader locks: i_mmap_lock and the i_lock. This routine allows + * multi-reader locks: invalidate_lock and the i_lock. This routine allows * various combinations of the locks to be obtained. * * The 3 locks should always be ordered so that the IO lock is obtained first, @@ -140,23 +140,23 @@ xfs_ilock_attr_map_shared( * * Basic locking order: * - * i_rwsem -> i_mmap_lock -> page_lock -> i_ilock + * i_rwsem -> invalidate_lock -> page_lock -> i_ilock * * mmap_lock locking order: * * i_rwsem -> page lock -> mmap_lock - * mmap_lock -> i_mmap_lock -> page_lock + * mmap_lock -> invalidate_lock -> page_lock * * The difference in mmap_lock locking order mean that we cannot hold the - * i_mmap_lock over syscall based read(2)/write(2) based IO. These IO paths can - * fault in pages during copy in/out (for buffered IO) or require the mmap_lock - * in get_user_pages() to map the user pages into the kernel address space for - * direct IO. Similarly the i_rwsem cannot be taken inside a page fault because - * page faults already hold the mmap_lock. + * invalidate_lock over syscall based read(2)/write(2) based IO. These IO paths + * can fault in pages during copy in/out (for buffered IO) or require the + * mmap_lock in get_user_pages() to map the user pages into the kernel address + * space for direct IO. Similarly the i_rwsem cannot be taken inside a page + * fault because page faults already hold the mmap_lock. * * Hence to serialise fully against both syscall and mmap based IO, we need to - * take both the i_rwsem and the i_mmap_lock. These locks should *only* be both - * taken in places where we need to invalidate the page cache in a race + * take both the i_rwsem and the invalidate_lock. These locks should *only* be + * both taken in places where we need to invalidate the page cache in a race * free manner (e.g. truncate, hole punch and other extent manipulation * functions). */ @@ -188,10 +188,13 @@ xfs_ilock( XFS_IOLOCK_DEP(lock_flags)); } - if (lock_flags & XFS_MMAPLOCK_EXCL) - mrupdate_nested(&ip->i_mmaplock, XFS_MMAPLOCK_DEP(lock_flags)); - else if (lock_flags & XFS_MMAPLOCK_SHARED) - mraccess_nested(&ip->i_mmaplock, XFS_MMAPLOCK_DEP(lock_flags)); + if (lock_flags & XFS_MMAPLOCK_EXCL) { + down_write_nested(&VFS_I(ip)->i_mapping->invalidate_lock, + XFS_MMAPLOCK_DEP(lock_flags)); + } else if (lock_flags & XFS_MMAPLOCK_SHARED) { + down_read_nested(&VFS_I(ip)->i_mapping->invalidate_lock, + XFS_MMAPLOCK_DEP(lock_flags)); + } if (lock_flags & XFS_ILOCK_EXCL) mrupdate_nested(&ip->i_lock, XFS_ILOCK_DEP(lock_flags)); @@ -240,10 +243,10 @@ xfs_ilock_nowait( } if (lock_flags & XFS_MMAPLOCK_EXCL) { - if (!mrtryupdate(&ip->i_mmaplock)) + if (!down_write_trylock(&VFS_I(ip)->i_mapping->invalidate_lock)) goto out_undo_iolock; } else if (lock_flags & XFS_MMAPLOCK_SHARED) { - if (!mrtryaccess(&ip->i_mmaplock)) + if (!down_read_trylock(&VFS_I(ip)->i_mapping->invalidate_lock)) goto out_undo_iolock; } @@ -258,9 +261,9 @@ xfs_ilock_nowait( out_undo_mmaplock: if (lock_flags & XFS_MMAPLOCK_EXCL) - mrunlock_excl(&ip->i_mmaplock); + up_write(&VFS_I(ip)->i_mapping->invalidate_lock); else if (lock_flags & XFS_MMAPLOCK_SHARED) - mrunlock_shared(&ip->i_mmaplock); + up_read(&VFS_I(ip)->i_mapping->invalidate_lock); out_undo_iolock: if (lock_flags & XFS_IOLOCK_EXCL) up_write(&VFS_I(ip)->i_rwsem); @@ -307,9 +310,9 @@ xfs_iunlock( up_read(&VFS_I(ip)->i_rwsem); if (lock_flags & XFS_MMAPLOCK_EXCL) - mrunlock_excl(&ip->i_mmaplock); + up_write(&VFS_I(ip)->i_mapping->invalidate_lock); else if (lock_flags & XFS_MMAPLOCK_SHARED) - mrunlock_shared(&ip->i_mmaplock); + up_read(&VFS_I(ip)->i_mapping->invalidate_lock); if (lock_flags & XFS_ILOCK_EXCL) mrunlock_excl(&ip->i_lock); @@ -335,7 +338,7 @@ xfs_ilock_demote( if (lock_flags & XFS_ILOCK_EXCL) mrdemote(&ip->i_lock); if (lock_flags & XFS_MMAPLOCK_EXCL) - mrdemote(&ip->i_mmaplock); + downgrade_write(&VFS_I(ip)->i_mapping->invalidate_lock); if (lock_flags & XFS_IOLOCK_EXCL) downgrade_write(&VFS_I(ip)->i_rwsem); @@ -375,9 +378,8 @@ xfs_isilocked( } if (lock_flags & (XFS_MMAPLOCK_EXCL|XFS_MMAPLOCK_SHARED)) { - if (!(lock_flags & XFS_MMAPLOCK_SHARED)) - return !!ip->i_mmaplock.mr_writer; - return rwsem_is_locked(&ip->i_mmaplock.mr_lock); + return __xfs_rwsem_islocked(&VFS_I(ip)->i_rwsem, + (lock_flags & XFS_IOLOCK_SHARED)); } if (lock_flags & (XFS_IOLOCK_EXCL | XFS_IOLOCK_SHARED)) { diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h index 4b5202ae8ebb..e0ae905554e2 100644 --- a/fs/xfs/xfs_inode.h +++ b/fs/xfs/xfs_inode.h @@ -40,7 +40,6 @@ typedef struct xfs_inode { /* Transaction and locking information. */ struct xfs_inode_log_item *i_itemp; /* logging information */ mrlock_t i_lock; /* inode lock */ - mrlock_t i_mmaplock; /* inode mmap IO lock */ atomic_t i_pincount; /* inode pin count */ /* diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c index 2c9e26a44546..102cbd606633 100644 --- a/fs/xfs/xfs_super.c +++ b/fs/xfs/xfs_super.c @@ -709,8 +709,6 @@ xfs_fs_inode_init_once( atomic_set(&ip->i_pincount, 0); spin_lock_init(&ip->i_flags_lock); - mrlock_init(&ip->i_mmaplock, MRLOCK_ALLOW_EQUAL_PRI|MRLOCK_BARRIER, - "xfsino", ip->i_ino); mrlock_init(&ip->i_lock, MRLOCK_ALLOW_EQUAL_PRI|MRLOCK_BARRIER, "xfsino", ip->i_ino); } -- cgit v1.2.3 From d2c292d84c4983424938f32c9c247f6ab8719769 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Mon, 24 May 2021 13:17:49 +0200 Subject: xfs: Convert double locking of MMAPLOCK to use VFS helpers 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" Reviewed-by: Darrick J. Wong Reviewed-by: Christoph Hellwig Signed-off-by: Jan Kara --- fs/xfs/xfs_bmap_util.c | 15 ++++++++------- fs/xfs/xfs_inode.c | 37 +++++++++++-------------------------- 2 files changed, 19 insertions(+), 33 deletions(-) (limited to 'fs/xfs/xfs_inode.c') diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c index 213a97a921bb..1cd3f940fa6a 100644 --- a/fs/xfs/xfs_bmap_util.c +++ b/fs/xfs/xfs_bmap_util.c @@ -1626,7 +1626,6 @@ 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; @@ -1638,8 +1637,8 @@ 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)) { @@ -1711,7 +1710,6 @@ 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); @@ -1830,13 +1828,16 @@ 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 d6a8ac76b45d..3c0bb21453dc 100644 --- a/fs/xfs/xfs_inode.c +++ b/fs/xfs/xfs_inode.c @@ -552,12 +552,10 @@ again: } /* - * 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( @@ -575,15 +573,8 @@ 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) { @@ -3748,11 +3739,8 @@ 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; } @@ -3762,12 +3750,9 @@ 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)); } -- cgit v1.2.3