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/btrfs_inode.h b/fs/btrfs/btrfs_inode.h
index 634608d2..9b9b15f 100644
--- a/fs/btrfs/btrfs_inode.h
+++ b/fs/btrfs/btrfs_inode.h
@@ -51,6 +51,9 @@
/* held while logging the inode in tree-log.c */
struct mutex log_mutex;
+ /* held while doing delalloc reservations */
+ struct mutex delalloc_mutex;
+
/* used to order data wrt metadata */
struct btrfs_ordered_inode_tree ordered_tree;
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 556f9aa..e0ad5f0 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -4345,12 +4345,11 @@
/* Need to be holding the i_mutex here if we aren't free space cache */
if (btrfs_is_free_space_inode(root, inode))
flush = 0;
- else
- WARN_ON(!mutex_is_locked(&inode->i_mutex));
if (flush && btrfs_transaction_in_commit(root->fs_info))
schedule_timeout(1);
+ mutex_lock(&BTRFS_I(inode)->delalloc_mutex);
num_bytes = ALIGN(num_bytes, root->sectorsize);
spin_lock(&BTRFS_I(inode)->lock);
@@ -4405,6 +4404,7 @@
btrfs_ino(inode),
to_free, 0);
}
+ mutex_unlock(&BTRFS_I(inode)->delalloc_mutex);
return ret;
}
@@ -4415,6 +4415,7 @@
}
BTRFS_I(inode)->reserved_extents += nr_extents;
spin_unlock(&BTRFS_I(inode)->lock);
+ mutex_unlock(&BTRFS_I(inode)->delalloc_mutex);
if (to_reserve)
trace_btrfs_space_reservation(root->fs_info,"delalloc",
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);
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 7fdf22c..6834be4 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -868,10 +868,8 @@
return 0;
file_end = (isize - 1) >> PAGE_CACHE_SHIFT;
- mutex_lock(&inode->i_mutex);
ret = btrfs_delalloc_reserve_space(inode,
num_pages << PAGE_CACHE_SHIFT);
- mutex_unlock(&inode->i_mutex);
if (ret)
return ret;
again:
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index efe9f79..8c1aae2 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -2949,9 +2949,7 @@
index = (cluster->start - offset) >> PAGE_CACHE_SHIFT;
last_index = (cluster->end - offset) >> PAGE_CACHE_SHIFT;
while (index <= last_index) {
- mutex_lock(&inode->i_mutex);
ret = btrfs_delalloc_reserve_metadata(inode, PAGE_CACHE_SIZE);
- mutex_unlock(&inode->i_mutex);
if (ret)
goto out;