As btrfs uses delay allocation mechanism and data=order mode, there can be
a period window, during which we sub delalloc_bytes and add_inode_bytes,
and we may get a value of '0' referred to inode's blocks via 'ls -lis'.
ino:291 blocks:198656 i_blocks:0 i_bytes:0 delalloc_bytes:101711872
ino:291 blocks:198656 i_blocks:0 i_bytes:0 delalloc_bytes:101711872
<---------
ino:291 blocks:0 i_blocks:0 i_bytes:0 delalloc_bytes:0 | THE
ino:291 blocks:0 i_blocks:0 i_bytes:0 delalloc_bytes:0 | WINDOW
<---------
ino:291 blocks:819200 i_blocks:819200 i_bytes:0 delalloc_bytes:0
This may make btrfs's users confused.
Hence, we use anther counter for the number of delalloc bytes in flight
that are accounted for in coordination with inode_add_bytes to ensure
correct output results.
Signed-off-by: Liu Bo <liubo2009@xxxxxxxxxxxxxx>
---
fs/btrfs/btrfs_inode.h | 8 ++++++--
fs/btrfs/inode.c | 15 ++++++++++++---
2 files changed, 18 insertions(+), 5 deletions(-)
diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h
index 31337df..1e0dc82 100644
--- a/fs/btrfs/btrfs_inode.h
+++ b/fs/btrfs/btrfs_inode.h
@@ -93,9 +93,13 @@ struct btrfs_inode {
*/
u64 logged_trans;
- /* total number of bytes pending delalloc, used by stat to calc the
- * real block usage of the file
+ /*
+ * total number of bytes pending delalloc, used by stat to
+ * calc the real block usage of the file.
*/
+ u64 pending_bytes;
+
+ /* total number of bytes pending delalloc */
u64 delalloc_bytes;
/* total number of bytes that may be used for this inode for
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index e01a084..70bd01d 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -106,6 +106,13 @@ static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
return err;
}
+static void btrfs_inode_add_bytes(struct inode *inode, loff_t bytes)
+{
+ if (BTRFS_I(inode)->pending_bytes >= bytes)
+ BTRFS_I(inode)->pending_bytes -= bytes;
+ inode_add_bytes(inode, bytes);
+}
+
/*
* this does all the hard work for inserting an inline extent into
* the btree. The caller should have done a btrfs_drop_extents so that
@@ -144,7 +151,7 @@ static noinline int insert_inline_extent(struct btrfs_trans_handle *trans,
btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
datasize = btrfs_file_extent_calc_inline_size(cur_size);
- inode_add_bytes(inode, size);
+ btrfs_inode_add_bytes(inode, size);
ret = btrfs_insert_empty_item(trans, root, path, &key,
datasize);
BUG_ON(ret);
@@ -1346,6 +1353,7 @@ static int btrfs_set_bit_hook(struct inode *inode,
spin_lock(&root->fs_info->delalloc_lock);
BTRFS_I(inode)->delalloc_bytes += len;
+ BTRFS_I(inode)->pending_bytes += len;
root->fs_info->delalloc_bytes += len;
if (do_list && list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
@@ -1685,7 +1693,7 @@ static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
btrfs_mark_buffer_dirty(leaf);
- inode_add_bytes(inode, num_bytes);
+ btrfs_inode_add_bytes(inode, num_bytes);
ins.objectid = disk_bytenr;
ins.offset = disk_num_bytes;
@@ -6726,6 +6734,7 @@ struct inode *btrfs_alloc_inode(struct super_block *sb)
ei->last_trans = 0;
ei->last_sub_trans = 0;
ei->logged_trans = 0;
+ ei->pending_bytes = 0;
ei->delalloc_bytes = 0;
ei->reserved_bytes = 0;
ei->disk_i_size = 0;
@@ -6901,7 +6910,7 @@ static int btrfs_getattr(struct vfsmount *mnt,
stat->dev = BTRFS_I(inode)->root->anon_super.s_dev;
stat->blksize = PAGE_CACHE_SIZE;
stat->blocks = (inode_get_bytes(inode) +
- BTRFS_I(inode)->delalloc_bytes) >> 9;
+ BTRFS_I(inode)->pending_bytes) >> 9;
return 0;
}
--
1.6.5.2
--
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