Josef Bacik
2012-Jan-13 17:08 UTC
[PATCH] 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>
---
fs/btrfs/btrfs_inode.h | 3 +++
fs/btrfs/extent-tree.c | 5 +++--
fs/btrfs/inode.c | 11 +----------
fs/btrfs/ioctl.c | 2 --
fs/btrfs/relocation.c | 2 --
5 files changed, 7 insertions(+), 16 deletions(-)
diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h
index 634608d..9b9b15f 100644
--- a/fs/btrfs/btrfs_inode.h
+++ b/fs/btrfs/btrfs_inode.h
@@ -51,6 +51,9 @@ struct btrfs_inode {
/* 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 673d32e..5519c65 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -4245,12 +4245,11 @@ int btrfs_delalloc_reserve_metadata(struct inode *inode,
u64 num_bytes)
/* 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);
@@ -4305,6 +4304,7 @@ int btrfs_delalloc_reserve_metadata(struct inode *inode,
u64 num_bytes)
btrfs_ino(inode),
to_free, 0);
}
+ mutex_unlock(&BTRFS_I(inode)->delalloc_mutex);
return ret;
}
@@ -4315,6 +4315,7 @@ int btrfs_delalloc_reserve_metadata(struct inode *inode,
u64 num_bytes)
}
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 85b8b90..f26fa6b 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -2239,14 +2239,7 @@ int btrfs_orphan_cleanup(struct btrfs_root *root)
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++;
}
@@ -6417,10 +6410,7 @@ int btrfs_page_mkwrite(struct vm_area_struct *vma, struct
vm_fault *vmf)
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) {
@@ -6764,6 +6754,7 @@ struct inode *btrfs_alloc_inode(struct super_block *sb)
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 c04f02c..40eaa9f 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -858,10 +858,8 @@ static int cluster_pages_for_defrag(struct inode *inode,
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 cfb5543..dff29d5 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -2947,9 +2947,7 @@ static int relocate_file_extent_cluster(struct inode
*inode,
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;
--
1.7.5.2
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