Btrfs: add a delalloc mutex to inodes for delalloc reservations
I was using i_mutex for this, but we're getting bogus lockdep warnings by doing
that and theres no real way to get rid of those, so just stop using i_mutex to
protect delalloc metadata reservations and use a delalloc mutex instead. This
shouldn't be contended often at all, only if you are writing and mmap writing to
the file at the same time. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 619742d..5977987 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -2239,14 +2239,7 @@
continue;
}
nr_truncate++;
- /*
- * Need to hold the imutex for reservation purposes, not
- * a huge deal here but I have a WARN_ON in
- * btrfs_delalloc_reserve_space to catch offenders.
- */
- mutex_lock(&inode->i_mutex);
ret = btrfs_truncate(inode);
- mutex_unlock(&inode->i_mutex);
} else {
nr_unlink++;
}
@@ -6411,10 +6404,7 @@
u64 page_start;
u64 page_end;
- /* Need this to keep space reservations serialized */
- mutex_lock(&inode->i_mutex);
ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
- mutex_unlock(&inode->i_mutex);
if (!ret)
ret = btrfs_update_time(vma->vm_file);
if (ret) {
@@ -6758,6 +6748,7 @@
extent_io_tree_init(&ei->io_tree, &inode->i_data);
extent_io_tree_init(&ei->io_failure_tree, &inode->i_data);
mutex_init(&ei->log_mutex);
+ mutex_init(&ei->delalloc_mutex);
btrfs_ordered_inode_tree_init(&ei->ordered_tree);
INIT_LIST_HEAD(&ei->i_orphan);
INIT_LIST_HEAD(&ei->delalloc_inodes);