Commit e18e4809 authored by Chris Mason's avatar Chris Mason

Btrfs: Add mount -o ssd, which includes optimizations for seek free storage

Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent 04005cc7
......@@ -351,6 +351,7 @@ struct btrfs_fs_info {
spinlock_t delalloc_lock;
spinlock_t new_trans_lock;
u64 delalloc_bytes;
u64 last_alloc;
};
/*
* in ram representation of the tree. extent_root is used for all allocations
......@@ -444,6 +445,7 @@ struct btrfs_root {
#define BTRFS_MOUNT_NODATASUM (1 << 0)
#define BTRFS_MOUNT_NODATACOW (1 << 1)
#define BTRFS_MOUNT_NOBARRIER (1 << 2)
#define BTRFS_MOUNT_SSD (1 << 3)
#define btrfs_clear_opt(o, opt) ((o) &= ~BTRFS_MOUNT_##opt)
#define btrfs_set_opt(o, opt) ((o) |= BTRFS_MOUNT_##opt)
......
......@@ -193,6 +193,7 @@ int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
}
eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
read_extent_buffer_pages(tree, eb, start + PAGE_CACHE_SIZE, 1);
btrfs_clear_buffer_defrag(eb);
found_start = btrfs_header_bytenr(eb);
if (found_start != start) {
printk("warning: eb start incorrect %Lu buffer %Lu len %lu\n",
......@@ -676,6 +677,8 @@ struct btrfs_root *open_ctree(struct super_block *sb)
fs_info->do_barriers = 1;
fs_info->closing = 0;
fs_info->total_pinned = 0;
fs_info->last_alloc = 0;
#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
INIT_WORK(&fs_info->trans_work, btrfs_transaction_cleaner, fs_info);
#else
......
......@@ -1431,6 +1431,19 @@ static int noinline find_free_extent(struct btrfs_trans_handle *trans,
data = BTRFS_BLOCK_GROUP_MIXED;
}
/* for SSD, cluster allocations together as much as possible */
if (btrfs_test_opt(root, SSD)) {
if (!data) {
if (root->fs_info->last_alloc)
hint_byte = root->fs_info->last_alloc;
else {
hint_byte = hint_byte &
~((u64)BTRFS_BLOCK_GROUP_SIZE - 1);
empty_size += 16 * 1024 * 1024;
}
}
}
search_end = min(search_end,
btrfs_super_total_bytes(&info->super_copy));
if (hint_byte) {
......@@ -1456,6 +1469,19 @@ static int noinline find_free_extent(struct btrfs_trans_handle *trans,
}
search_start = find_search_start(root, &block_group, search_start,
total_needed, data);
if (!data && btrfs_test_opt(root, SSD) && info->last_alloc &&
search_start != info->last_alloc) {
info->last_alloc = 0;
if (!empty_size) {
empty_size += 16 * 1024 * 1024;
total_needed += empty_size;
}
search_start = find_search_start(root, &block_group,
search_start, total_needed,
data);
}
search_start = stripe_align(root, search_start);
cached_start = search_start;
btrfs_init_path(path);
......@@ -1610,6 +1636,8 @@ static int noinline find_free_extent(struct btrfs_trans_handle *trans,
error:
btrfs_release_path(root, path);
btrfs_free_path(path);
if (btrfs_test_opt(root, SSD) && !ret && !data)
info->last_alloc = ins->objectid + ins->offset;
return ret;
}
/*
......@@ -1778,6 +1806,7 @@ struct extent_buffer *__btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
buf->start, buf->start + buf->len - 1,
EXTENT_CSUM, GFP_NOFS);
buf->flags |= EXTENT_CSUM;
if (!btrfs_test_opt(root, SSD))
btrfs_set_buffer_defrag(buf);
trans->blocks_used++;
return buf;
......
......@@ -64,7 +64,7 @@ static void btrfs_put_super (struct super_block * sb)
enum {
Opt_subvol, Opt_nodatasum, Opt_nodatacow, Opt_max_extent,
Opt_alloc_start, Opt_nobarrier, Opt_err,
Opt_alloc_start, Opt_nobarrier, Opt_ssd, Opt_err,
};
static match_table_t tokens = {
......@@ -74,6 +74,7 @@ static match_table_t tokens = {
{Opt_nobarrier, "nobarrier"},
{Opt_max_extent, "max_extent=%s"},
{Opt_alloc_start, "alloc_start=%s"},
{Opt_ssd, "ssd"},
{Opt_err, NULL}
};
......@@ -149,6 +150,12 @@ static int parse_options (char * options,
btrfs_set_opt(info->mount_opt, NODATASUM);
}
break;
case Opt_ssd:
if (info) {
printk("btrfs: use ssd allocation scheme\n");
btrfs_set_opt(info->mount_opt, SSD);
}
break;
case Opt_nobarrier:
if (info) {
printk("btrfs: turning off barriers\n");
......
......@@ -57,6 +57,7 @@ static int join_transaction(struct btrfs_root *root)
BUG_ON(!cur_trans);
root->fs_info->generation++;
root->fs_info->running_transaction = cur_trans;
root->fs_info->last_alloc = 0;
cur_trans->num_writers = 1;
cur_trans->num_joined = 0;
cur_trans->transid = root->fs_info->generation;
......
......@@ -179,6 +179,9 @@ int btrfs_defrag_leaves(struct btrfs_trans_handle *trans,
if (root->ref_cows == 0 && !is_extent)
goto out;
if (btrfs_test_opt(root, SSD))
goto out;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
......
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