/*
* 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,
*
* 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).
*/
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));
}
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;
}
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);
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);
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);
}
#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)) {
}
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)) {
- 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
}
/*
- * 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(
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) {
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;
}
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));
}
projects / linux.git / blobdiff