Btrfs: add better -ENOSPC handling
This is a step in the direction of better -ENOSPC handling. Instead of
checking the global bytes counter we check the space_info bytes counters to
make sure we have enough space.
If we don't we go ahead and try to allocate a new chunk, and then if that fails
we return -ENOSPC. This patch adds two counters to btrfs_space_info,
bytes_delalloc and bytes_may_use.
bytes_delalloc account for extents we've actually setup for delalloc and will
be allocated at some point down the line.
bytes_may_use is to keep track of how many bytes we may use for delalloc at
some point. When we actually set the extent_bit for the delalloc bytes we
subtract the reserved bytes from the bytes_may_use counter. This keeps us from
not actually being able to allocate space for any delalloc bytes.
Signed-off-by: Josef Bacik <jbacik@redhat.com>
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 3cee77a..7d4f948 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -102,34 +102,6 @@
}
/*
- * a very lame attempt at stopping writes when the FS is 85% full. There
- * are countless ways this is incorrect, but it is better than nothing.
- */
-int btrfs_check_free_space(struct btrfs_root *root, u64 num_required,
- int for_del)
-{
- u64 total;
- u64 used;
- u64 thresh;
- int ret = 0;
-
- spin_lock(&root->fs_info->delalloc_lock);
- total = btrfs_super_total_bytes(&root->fs_info->super_copy);
- used = btrfs_super_bytes_used(&root->fs_info->super_copy);
- if (for_del)
- thresh = total * 90;
- else
- thresh = total * 85;
-
- do_div(thresh, 100);
-
- if (used + root->fs_info->delalloc_bytes + num_required > thresh)
- ret = -ENOSPC;
- spin_unlock(&root->fs_info->delalloc_lock);
- return ret;
-}
-
-/*
* 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
* no overlapping inline items exist in the btree
@@ -1190,6 +1162,7 @@
*/
if (!(old & EXTENT_DELALLOC) && (bits & EXTENT_DELALLOC)) {
struct btrfs_root *root = BTRFS_I(inode)->root;
+ btrfs_delalloc_reserve_space(root, inode, end - start + 1);
spin_lock(&root->fs_info->delalloc_lock);
BTRFS_I(inode)->delalloc_bytes += end - start + 1;
root->fs_info->delalloc_bytes += end - start + 1;
@@ -1223,9 +1196,12 @@
(unsigned long long)end - start + 1,
(unsigned long long)
root->fs_info->delalloc_bytes);
+ btrfs_delalloc_free_space(root, inode, (u64)-1);
root->fs_info->delalloc_bytes = 0;
BTRFS_I(inode)->delalloc_bytes = 0;
} else {
+ btrfs_delalloc_free_space(root, inode,
+ end - start + 1);
root->fs_info->delalloc_bytes -= end - start + 1;
BTRFS_I(inode)->delalloc_bytes -= end - start + 1;
}
@@ -2245,10 +2221,6 @@
root = BTRFS_I(dir)->root;
- ret = btrfs_check_free_space(root, 1, 1);
- if (ret)
- goto fail;
-
trans = btrfs_start_transaction(root, 1);
btrfs_set_trans_block_group(trans, dir);
@@ -2261,7 +2233,6 @@
nr = trans->blocks_used;
btrfs_end_transaction_throttle(trans, root);
-fail:
btrfs_btree_balance_dirty(root, nr);
return ret;
}
@@ -2284,10 +2255,6 @@
return -ENOTEMPTY;
}
- ret = btrfs_check_free_space(root, 1, 1);
- if (ret)
- goto fail;
-
trans = btrfs_start_transaction(root, 1);
btrfs_set_trans_block_group(trans, dir);
@@ -2304,7 +2271,6 @@
fail_trans:
nr = trans->blocks_used;
ret = btrfs_end_transaction_throttle(trans, root);
-fail:
btrfs_btree_balance_dirty(root, nr);
if (ret && !err)
@@ -2818,7 +2784,7 @@
if (size <= hole_start)
return 0;
- err = btrfs_check_free_space(root, 1, 0);
+ err = btrfs_check_metadata_free_space(root);
if (err)
return err;
@@ -3014,6 +2980,7 @@
bi->last_trans = 0;
bi->logged_trans = 0;
bi->delalloc_bytes = 0;
+ bi->reserved_bytes = 0;
bi->disk_i_size = 0;
bi->flags = 0;
bi->index_cnt = (u64)-1;
@@ -3035,6 +3002,7 @@
inode->i_ino = args->ino;
init_btrfs_i(inode);
BTRFS_I(inode)->root = args->root;
+ btrfs_set_inode_space_info(args->root, inode);
return 0;
}
@@ -3455,6 +3423,7 @@
BTRFS_I(inode)->index_cnt = 2;
BTRFS_I(inode)->root = root;
BTRFS_I(inode)->generation = trans->transid;
+ btrfs_set_inode_space_info(root, inode);
if (mode & S_IFDIR)
owner = 0;
@@ -3602,7 +3571,7 @@
if (!new_valid_dev(rdev))
return -EINVAL;
- err = btrfs_check_free_space(root, 1, 0);
+ err = btrfs_check_metadata_free_space(root);
if (err)
goto fail;
@@ -3665,7 +3634,7 @@
u64 objectid;
u64 index = 0;
- err = btrfs_check_free_space(root, 1, 0);
+ err = btrfs_check_metadata_free_space(root);
if (err)
goto fail;
trans = btrfs_start_transaction(root, 1);
@@ -3733,7 +3702,7 @@
return -ENOENT;
btrfs_inc_nlink(inode);
- err = btrfs_check_free_space(root, 1, 0);
+ err = btrfs_check_metadata_free_space(root);
if (err)
goto fail;
err = btrfs_set_inode_index(dir, &index);
@@ -3779,7 +3748,7 @@
u64 index = 0;
unsigned long nr = 1;
- err = btrfs_check_free_space(root, 1, 0);
+ err = btrfs_check_metadata_free_space(root);
if (err)
goto out_unlock;
@@ -4336,7 +4305,7 @@
u64 page_start;
u64 page_end;
- ret = btrfs_check_free_space(root, PAGE_CACHE_SIZE, 0);
+ ret = btrfs_check_data_free_space(root, inode, PAGE_CACHE_SIZE);
if (ret)
goto out;
@@ -4349,6 +4318,7 @@
if ((page->mapping != inode->i_mapping) ||
(page_start >= size)) {
+ btrfs_free_reserved_data_space(root, inode, PAGE_CACHE_SIZE);
/* page got truncated out from underneath us */
goto out_unlock;
}
@@ -4631,7 +4601,7 @@
if (old_inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
return -EXDEV;
- ret = btrfs_check_free_space(root, 1, 0);
+ ret = btrfs_check_metadata_free_space(root);
if (ret)
goto out_unlock;
@@ -4749,7 +4719,7 @@
if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
return -ENAMETOOLONG;
- err = btrfs_check_free_space(root, 1, 0);
+ err = btrfs_check_metadata_free_space(root);
if (err)
goto out_fail;
