Josef Bacik
2010-Sep-21 18:28 UTC
[PATCH] Btrfs: create special free space cache inode FORMAT CHANGE V2
In order to save free space cache, we need an inode to hold the data, and we
need a special item to point at the right inode for the right block group. So
first, create a special item that will point to the right inode, and the number
of extent entries we will have and the number of bitmaps we will have. We
truncate and pre-allocate space everytime to make sure it''s uptodate.
This is a disk format change, HOWEVER, you need to mount with -o space_cache in
order to get it, otherwise this feature won''t be enabled.
Signed-off-by: Josef Bacik <josef@redhat.com>
---
V1->V2: I screwed up the incompat flag so you would still get half of the
free
space cache functionality, just enough to blow everything up. I''ve
fixed the
incompat flags so they make more sense now. This doesn''t affect any of
the
other patches in this series.
fs/btrfs/ctree.h | 71 +++++++++++++-
fs/btrfs/disk-io.c | 3 +-
fs/btrfs/extent-tree.c | 220 +++++++++++++++++++++++++++++++++++++++++-
fs/btrfs/free-space-cache.c | 155 ++++++++++++++++++++++++++++++
fs/btrfs/free-space-cache.h | 11 ++
fs/btrfs/inode.c | 92 +++++++++++++++---
fs/btrfs/relocation.c | 91 +++++++++++++++++-
fs/btrfs/super.c | 11 ++-
fs/btrfs/transaction.c | 41 ++++++--
fs/btrfs/transaction.h | 4 +
10 files changed, 654 insertions(+), 45 deletions(-)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index e9bf864..621bf90 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -99,6 +99,9 @@ struct btrfs_ordered_sum;
*/
#define BTRFS_EXTENT_CSUM_OBJECTID -10ULL
+/* For storing free space cache */
+#define BTRFS_FREE_SPACE_OBJECTID -11ULL
+
/* dummy objectid represents multiple objectids */
#define BTRFS_MULTIPLE_OBJECTIDS -255ULL
@@ -265,6 +268,22 @@ struct btrfs_chunk {
/* additional stripes go here */
} __attribute__ ((__packed__));
+#define BTRFS_FREE_SPACE_EXTENT 1
+#define BTRFS_FREE_SPACE_BITMAP 2
+
+struct btrfs_free_space_entry {
+ __le64 offset;
+ __le64 bytes;
+ u8 type;
+} __attribute__ ((__packed__));
+
+struct btrfs_free_space_header {
+ struct btrfs_disk_key location;
+ __le64 generation;
+ __le64 num_entries;
+ __le64 num_bitmaps;
+} __attribute__ ((__packed__));
+
static inline unsigned long btrfs_chunk_item_size(int num_stripes)
{
BUG_ON(num_stripes == 0);
@@ -375,13 +394,15 @@ struct btrfs_super_block {
* ones specified below then we will fail to mount
*/
#define BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF (1ULL << 0)
-#define BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL (2ULL << 0)
+#define BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL (1ULL << 1)
+#define BTRFS_FEATURE_INCOMPAT_SPACE_CACHE (1ULL << 2)
#define BTRFS_FEATURE_COMPAT_SUPP 0ULL
#define BTRFS_FEATURE_COMPAT_RO_SUPP 0ULL
-#define BTRFS_FEATURE_INCOMPAT_SUPP \
- (BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF | \
- BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL)
+#define BTRFS_FEATURE_INCOMPAT_SUPP \
+ (BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF | \
+ BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL | \
+ BTRFS_FEATURE_INCOMPAT_SPACE_CACHE)
/*
* A leaf is full of items. offset and size tell us where to find
@@ -750,6 +771,14 @@ enum btrfs_caching_type {
BTRFS_CACHE_FINISHED = 2,
};
+enum btrfs_disk_cache_state {
+ BTRFS_DC_WRITTEN = 0,
+ BTRFS_DC_ERROR = 1,
+ BTRFS_DC_CLEAR = 2,
+ BTRFS_DC_SETUP = 3,
+ BTRFS_DC_NEED_WRITE = 4,
+};
+
struct btrfs_caching_control {
struct list_head list;
struct mutex mutex;
@@ -763,6 +792,7 @@ struct btrfs_block_group_cache {
struct btrfs_key key;
struct btrfs_block_group_item item;
struct btrfs_fs_info *fs_info;
+ struct inode *inode;
spinlock_t lock;
u64 pinned;
u64 reserved;
@@ -773,8 +803,11 @@ struct btrfs_block_group_cache {
int extents_thresh;
int free_extents;
int total_bitmaps;
- int ro;
- int dirty;
+ int ro:1;
+ int dirty:1;
+ int iref:1;
+
+ int disk_cache_state;
/* cache tracking stuff */
int cached;
@@ -1665,6 +1698,27 @@ static inline void btrfs_set_dir_item_key(struct
extent_buffer *eb,
write_eb_member(eb, item, struct btrfs_dir_item, location, key);
}
+BTRFS_SETGET_FUNCS(free_space_entries, struct btrfs_free_space_header,
+ num_entries, 64);
+BTRFS_SETGET_FUNCS(free_space_bitmaps, struct btrfs_free_space_header,
+ num_bitmaps, 64);
+BTRFS_SETGET_FUNCS(free_space_generation, struct btrfs_free_space_header,
+ generation, 64);
+
+static inline void btrfs_free_space_key(struct extent_buffer *eb,
+ struct btrfs_free_space_header *h,
+ struct btrfs_disk_key *key)
+{
+ read_eb_member(eb, h, struct btrfs_free_space_header, location, key);
+}
+
+static inline void btrfs_set_free_space_key(struct extent_buffer *eb,
+ struct btrfs_free_space_header *h,
+ struct btrfs_disk_key *key)
+{
+ write_eb_member(eb, h, struct btrfs_free_space_header, location, key);
+}
+
/* struct btrfs_disk_key */
BTRFS_SETGET_STACK_FUNCS(disk_key_objectid, struct btrfs_disk_key,
objectid, 64);
@@ -2115,6 +2169,7 @@ int btrfs_set_block_group_ro(struct btrfs_root *root,
struct btrfs_block_group_cache *cache);
int btrfs_set_block_group_rw(struct btrfs_root *root,
struct btrfs_block_group_cache *cache);
+void btrfs_put_block_group_cache(struct btrfs_fs_info *info);
/* ctree.c */
int btrfs_bin_search(struct extent_buffer *eb, struct btrfs_key *key,
int level, int *slot);
@@ -2426,6 +2481,10 @@ void btrfs_run_delayed_iputs(struct btrfs_root *root);
int btrfs_prealloc_file_range(struct inode *inode, int mode,
u64 start, u64 num_bytes, u64 min_size,
loff_t actual_len, u64 *alloc_hint);
+int btrfs_prealloc_file_range_trans(struct inode *inode,
+ struct btrfs_trans_handle *trans, int mode,
+ u64 start, u64 num_bytes, u64 min_size,
+ loff_t actual_len, u64 *alloc_hint);
extern const struct dentry_operations btrfs_dentry_operations;
/* ioctl.c */
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 34f7c37..163ee07 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1685,7 +1685,6 @@ struct btrfs_root *open_ctree(struct super_block *sb,
__setup_root(4096, 4096, 4096, 4096, tree_root,
fs_info, BTRFS_ROOT_TREE_OBJECTID);
-
bh = btrfs_read_dev_super(fs_devices->latest_bdev);
if (!bh)
goto fail_iput;
@@ -1993,6 +1992,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
if (!(sb->s_flags & MS_RDONLY)) {
down_read(&fs_info->cleanup_work_sem);
btrfs_orphan_cleanup(fs_info->fs_root);
+ btrfs_orphan_cleanup(fs_info->tree_root);
up_read(&fs_info->cleanup_work_sem);
}
@@ -2421,6 +2421,7 @@ int close_ctree(struct btrfs_root *root)
fs_info->closing = 1;
smp_mb();
+ btrfs_put_block_group_cache(fs_info);
if (!(fs_info->sb->s_flags & MS_RDONLY)) {
ret = btrfs_commit_super(root);
if (ret)
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index a46b64d..b8151ad 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -2688,6 +2688,109 @@ next_block_group(struct btrfs_root *root,
return cache;
}
+static int cache_save_setup(struct btrfs_block_group_cache *block_group,
+ struct btrfs_trans_handle *trans,
+ struct btrfs_path *path)
+{
+ struct btrfs_root *root = block_group->fs_info->tree_root;
+ struct inode *inode = NULL;
+ u64 alloc_hint = 0;
+ int num_pages = 0;
+ int retries = 0;
+ int ret = 0;
+
+ /*
+ * If this block group is smaller than 100 megs don''t bother caching
the
+ * block group.
+ */
+ if (block_group->key.offset < (100 * 1024 * 1024)) {
+ spin_lock(&block_group->lock);
+ block_group->disk_cache_state = BTRFS_DC_WRITTEN;
+ spin_unlock(&block_group->lock);
+ return 0;
+ }
+
+again:
+ inode = lookup_free_space_inode(root, block_group, path);
+ if (IS_ERR(inode) && PTR_ERR(inode) != -ENOENT) {
+ ret = PTR_ERR(inode);
+ btrfs_release_path(root, path);
+ goto out;
+ }
+
+ if (IS_ERR(inode)) {
+ BUG_ON(retries);
+ retries++;
+
+ if (block_group->ro)
+ goto out_free;
+
+ ret = create_free_space_inode(root, trans, block_group, path);
+ if (ret)
+ goto out_free;
+ goto again;
+ }
+
+ /*
+ * We want to set the generation to 0, that way if anything goes wrong
+ * from here on out we know not to trust this cache when we load up next
+ * time.
+ */
+ BTRFS_I(inode)->generation = 0;
+ ret = btrfs_update_inode(trans, root, inode);
+ WARN_ON(ret);
+
+ if (i_size_read(inode) > 0) {
+ ret = btrfs_truncate_free_space_cache(root, trans, path,
+ inode);
+ if (ret)
+ goto out_put;
+ }
+
+ spin_lock(&block_group->lock);
+ if (block_group->cached != BTRFS_CACHE_FINISHED) {
+ spin_unlock(&block_group->lock);
+ goto out_put;
+ }
+ spin_unlock(&block_group->lock);
+
+ num_pages = (int)div64_u64(block_group->key.offset, 1024 * 1024 * 1024);
+ if (!num_pages)
+ num_pages = 1;
+
+ /*
+ * Just to make absolutely sure we have enough space, we''re going to
+ * preallocate 12 pages worth of space for each block group. In
+ * practice we ought to use at most 8, but we need extra space so we can
+ * add our header and have a terminator between the extents and the
+ * bitmaps.
+ */
+ num_pages *= 16;
+ num_pages *= PAGE_CACHE_SIZE;
+
+ ret = btrfs_check_data_free_space(inode, num_pages);
+ if (ret)
+ goto out_put;
+
+ ret = btrfs_prealloc_file_range_trans(inode, trans, 0, 0, num_pages,
+ num_pages, num_pages,
+ &alloc_hint);
+ btrfs_free_reserved_data_space(inode, num_pages);
+out_put:
+ iput(inode);
+out_free:
+ btrfs_release_path(root, path);
+out:
+ spin_lock(&block_group->lock);
+ if (ret)
+ block_group->disk_cache_state = BTRFS_DC_ERROR;
+ else
+ block_group->disk_cache_state = BTRFS_DC_SETUP;
+ spin_unlock(&block_group->lock);
+
+ return ret;
+}
+
int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
@@ -2700,6 +2803,25 @@ int btrfs_write_dirty_block_groups(struct
btrfs_trans_handle *trans,
if (!path)
return -ENOMEM;
+again:
+ while (1) {
+ cache = btrfs_lookup_first_block_group(root->fs_info, last);
+ while (cache) {
+ if (cache->disk_cache_state == BTRFS_DC_CLEAR)
+ break;
+ cache = next_block_group(root, cache);
+ }
+ if (!cache) {
+ if (last == 0)
+ break;
+ last = 0;
+ continue;
+ }
+ err = cache_save_setup(cache, trans, path);
+ last = cache->key.objectid + cache->key.offset;
+ btrfs_put_block_group(cache);
+ }
+
while (1) {
if (last == 0) {
err = btrfs_run_delayed_refs(trans, root,
@@ -2709,6 +2831,11 @@ int btrfs_write_dirty_block_groups(struct
btrfs_trans_handle *trans,
cache = btrfs_lookup_first_block_group(root->fs_info, last);
while (cache) {
+ if (cache->disk_cache_state == BTRFS_DC_CLEAR) {
+ btrfs_put_block_group(cache);
+ goto again;
+ }
+
if (cache->dirty)
break;
cache = next_block_group(root, cache);
@@ -2883,11 +3010,16 @@ int btrfs_check_data_free_space(struct inode *inode, u64
bytes)
struct btrfs_space_info *data_sinfo;
struct btrfs_root *root = BTRFS_I(inode)->root;
u64 used;
- int ret = 0, committed = 0;
+ int ret = 0, committed = 0, alloc_chunk = 1;
/* make sure bytes are sectorsize aligned */
bytes = (bytes + root->sectorsize - 1) & ~((u64)root->sectorsize -
1);
+ if (root == root->fs_info->tree_root) {
+ alloc_chunk = 0;
+ committed = 1;
+ }
+
data_sinfo = BTRFS_I(inode)->space_info;
if (!data_sinfo)
goto alloc;
@@ -2906,7 +3038,7 @@ again:
* if we don''t have enough free bytes in this space then we need
* to alloc a new chunk.
*/
- if (!data_sinfo->full) {
+ if (!data_sinfo->full && alloc_chunk) {
u64 alloc_target;
data_sinfo->force_alloc = 1;
@@ -3777,12 +3909,13 @@ static int update_block_group(struct btrfs_trans_handle
*trans,
struct btrfs_root *root,
u64 bytenr, u64 num_bytes, int alloc)
{
- struct btrfs_block_group_cache *cache;
+ struct btrfs_block_group_cache *cache = NULL;
struct btrfs_fs_info *info = root->fs_info;
- int factor;
+ u64 features = btrfs_super_incompat_flags(&info->super_copy);
u64 total = num_bytes;
u64 old_val;
u64 byte_in_group;
+ int factor;
/* block accounting for super block */
spin_lock(&info->delalloc_lock);
@@ -3804,11 +3937,17 @@ static int update_block_group(struct btrfs_trans_handle
*trans,
factor = 2;
else
factor = 1;
+
byte_in_group = bytenr - cache->key.objectid;
WARN_ON(byte_in_group > cache->key.offset);
spin_lock(&cache->space_info->lock);
spin_lock(&cache->lock);
+
+ if (cache->disk_cache_state < BTRFS_DC_CLEAR &&
+ features & BTRFS_FEATURE_INCOMPAT_SPACE_CACHE)
+ cache->disk_cache_state = BTRFS_DC_CLEAR;
+
cache->dirty = 1;
old_val = btrfs_block_group_used(&cache->item);
num_bytes = min(total, cache->key.offset - byte_in_group);
@@ -7814,6 +7953,39 @@ out:
return ret;
}
+void btrfs_put_block_group_cache(struct btrfs_fs_info *info)
+{
+ struct btrfs_block_group_cache *block_group;
+ u64 last = 0;
+
+ while (1) {
+ struct inode *inode;
+
+ block_group = btrfs_lookup_first_block_group(info, last);
+ while (block_group) {
+ spin_lock(&block_group->lock);
+ if (block_group->iref)
+ break;
+ spin_unlock(&block_group->lock);
+ block_group = next_block_group(info->tree_root,
+ block_group);
+ }
+ if (!block_group) {
+ if (last == 0)
+ break;
+ last = 0;
+ continue;
+ }
+
+ inode = block_group->inode;
+ block_group->iref = 0;
+ spin_unlock(&block_group->lock);
+ iput(inode);
+ last = block_group->key.objectid + block_group->key.offset;
+ btrfs_put_block_group(block_group);
+ }
+}
+
int btrfs_free_block_groups(struct btrfs_fs_info *info)
{
struct btrfs_block_group_cache *block_group;
@@ -8032,6 +8204,7 @@ int btrfs_make_block_group(struct btrfs_trans_handle
*trans,
cache->key.offset = size;
cache->key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
cache->sectorsize = root->sectorsize;
+ cache->fs_info = root->fs_info;
/*
* we only want to have 32k of ram per block group for keeping track
@@ -8088,7 +8261,9 @@ int btrfs_remove_block_group(struct btrfs_trans_handle
*trans,
struct btrfs_path *path;
struct btrfs_block_group_cache *block_group;
struct btrfs_free_cluster *cluster;
+ struct btrfs_root *tree_root = root->fs_info->tree_root;
struct btrfs_key key;
+ struct inode *inode;
int ret;
root = root->fs_info->extent_root;
@@ -8097,8 +8272,6 @@ int btrfs_remove_block_group(struct btrfs_trans_handle
*trans,
BUG_ON(!block_group);
BUG_ON(!block_group->ro);
- memcpy(&key, &block_group->key, sizeof(key));
-
/* make sure this block group isn''t part of an allocation cluster */
cluster = &root->fs_info->data_alloc_cluster;
spin_lock(&cluster->refill_lock);
@@ -8117,6 +8290,39 @@ int btrfs_remove_block_group(struct btrfs_trans_handle
*trans,
path = btrfs_alloc_path();
BUG_ON(!path);
+ inode = lookup_free_space_inode(root, block_group, path);
+ if (!IS_ERR(inode)) {
+ btrfs_orphan_add(trans, inode);
+ clear_nlink(inode);
+ /* One for the block groups ref */
+ spin_lock(&block_group->lock);
+ if (block_group->iref) {
+ block_group->inode = NULL;
+ spin_unlock(&block_group->lock);
+ iput(inode);
+ } else {
+ spin_unlock(&block_group->lock);
+ }
+ /* One for our lookup ref */
+ iput(inode);
+ }
+
+ key.objectid = BTRFS_FREE_SPACE_OBJECTID;
+ key.offset = block_group->key.objectid;
+ key.type = 0;
+
+ ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1);
+ if (ret < 0)
+ goto out;
+ if (ret > 0)
+ btrfs_release_path(tree_root, path);
+ if (ret == 0) {
+ ret = btrfs_del_item(trans, tree_root, path);
+ if (ret)
+ goto out;
+ btrfs_release_path(tree_root, path);
+ }
+
spin_lock(&root->fs_info->block_group_cache_lock);
rb_erase(&block_group->cache_node,
&root->fs_info->block_group_cache_tree);
@@ -8140,6 +8346,8 @@ int btrfs_remove_block_group(struct btrfs_trans_handle
*trans,
block_group->space_info->bytes_readonly -= block_group->key.offset;
spin_unlock(&block_group->space_info->lock);
+ memcpy(&key, &block_group->key, sizeof(key));
+
btrfs_clear_space_info_full(root->fs_info);
btrfs_put_block_group(block_group);
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index f488fac..05efcc7 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -23,10 +23,165 @@
#include "ctree.h"
#include "free-space-cache.h"
#include "transaction.h"
+#include "disk-io.h"
#define BITS_PER_BITMAP (PAGE_CACHE_SIZE * 8)
#define MAX_CACHE_BYTES_PER_GIG (32 * 1024)
+struct inode *lookup_free_space_inode(struct btrfs_root *root,
+ struct btrfs_block_group_cache
+ *block_group, struct btrfs_path *path)
+{
+ struct btrfs_key key;
+ struct btrfs_key location;
+ struct btrfs_disk_key disk_key;
+ struct btrfs_free_space_header *header;
+ struct extent_buffer *leaf;
+ struct inode *inode = NULL;
+ int ret;
+
+ spin_lock(&block_group->lock);
+ if (block_group->inode)
+ inode = igrab(block_group->inode);
+ spin_unlock(&block_group->lock);
+ if (inode)
+ return inode;
+
+ key.objectid = BTRFS_FREE_SPACE_OBJECTID;
+ key.offset = block_group->key.objectid;
+ key.type = 0;
+
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ return ERR_PTR(ret);
+ if (ret > 0) {
+ btrfs_release_path(root, path);
+ return ERR_PTR(-ENOENT);
+ }
+
+ leaf = path->nodes[0];
+ header = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_free_space_header);
+ btrfs_free_space_key(leaf, header, &disk_key);
+ btrfs_disk_key_to_cpu(&location, &disk_key);
+ btrfs_release_path(root, path);
+
+ inode = btrfs_iget(root->fs_info->sb, &location, root, NULL);
+ if (!inode)
+ return ERR_PTR(-ENOENT);
+ if (IS_ERR(inode))
+ return inode;
+ if (is_bad_inode(inode)) {
+ iput(inode);
+ return ERR_PTR(-ENOENT);
+ }
+
+ spin_lock(&block_group->lock);
+ if (!root->fs_info->closing) {
+ block_group->inode = igrab(inode);
+ block_group->iref = 1;
+ }
+ spin_unlock(&block_group->lock);
+
+ return inode;
+}
+
+int create_free_space_inode(struct btrfs_root *root,
+ struct btrfs_trans_handle *trans,
+ struct btrfs_block_group_cache *block_group,
+ struct btrfs_path *path)
+{
+ struct btrfs_key key;
+ struct btrfs_disk_key disk_key;
+ struct btrfs_free_space_header *header;
+ struct btrfs_inode_item *inode_item;
+ struct extent_buffer *leaf;
+ u64 objectid;
+ int ret;
+
+ ret = btrfs_find_free_objectid(trans, root, 0, &objectid);
+ if (ret < 0)
+ return ret;
+
+ ret = btrfs_insert_empty_inode(trans, root, path, objectid);
+ if (ret)
+ return ret;
+
+ leaf = path->nodes[0];
+ inode_item = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_inode_item);
+ btrfs_item_key(leaf, &disk_key, path->slots[0]);
+ memset_extent_buffer(leaf, 0, (unsigned long)inode_item,
+ sizeof(*inode_item));
+ btrfs_set_inode_generation(leaf, inode_item, trans->transid);
+ btrfs_set_inode_size(leaf, inode_item, 0);
+ btrfs_set_inode_nbytes(leaf, inode_item, 0);
+ btrfs_set_inode_uid(leaf, inode_item, 0);
+ btrfs_set_inode_gid(leaf, inode_item, 0);
+ btrfs_set_inode_mode(leaf, inode_item, S_IFREG | 0600);
+ btrfs_set_inode_flags(leaf, inode_item, BTRFS_INODE_NOCOMPRESS |
+ BTRFS_INODE_PREALLOC | BTRFS_INODE_NODATASUM);
+ btrfs_set_inode_nlink(leaf, inode_item, 1);
+ btrfs_set_inode_transid(leaf, inode_item, trans->transid);
+ btrfs_set_inode_block_group(leaf, inode_item,
+ block_group->key.objectid);
+ btrfs_mark_buffer_dirty(leaf);
+ btrfs_release_path(root, path);
+
+ key.objectid = BTRFS_FREE_SPACE_OBJECTID;
+ key.offset = block_group->key.objectid;
+ key.type = 0;
+
+ ret = btrfs_insert_empty_item(trans, root, path, &key,
+ sizeof(struct btrfs_free_space_header));
+ if (ret < 0) {
+ btrfs_release_path(root, path);
+ return ret;
+ }
+ leaf = path->nodes[0];
+ header = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_free_space_header);
+ memset_extent_buffer(leaf, 0, (unsigned long)header, sizeof(*header));
+ btrfs_set_free_space_key(leaf, header, &disk_key);
+ btrfs_mark_buffer_dirty(leaf);
+ btrfs_release_path(root, path);
+
+ return 0;
+}
+
+int btrfs_truncate_free_space_cache(struct btrfs_root *root,
+ struct btrfs_trans_handle *trans,
+ struct btrfs_path *path,
+ struct inode *inode)
+{
+ loff_t oldsize;
+ int ret = 0;
+
+ trans->block_rsv = root->orphan_block_rsv;
+ ret = btrfs_block_rsv_check(trans, root,
+ root->orphan_block_rsv,
+ 0, 5);
+ if (ret)
+ return ret;
+
+ oldsize = i_size_read(inode);
+ btrfs_i_size_write(inode, 0);
+ truncate_pagecache(inode, oldsize, 0);
+
+ /*
+ * We don''t need an orphan item because truncating the free space
cache
+ * will never be split across transactions.
+ */
+ ret = btrfs_truncate_inode_items(trans, root, inode,
+ 0, BTRFS_EXTENT_DATA_KEY);
+ if (ret) {
+ WARN_ON(1);
+ return ret;
+ }
+
+ return btrfs_update_inode(trans, root, inode);
+}
+
static inline unsigned long offset_to_bit(u64 bitmap_start, u64 sectorsize,
u64 offset)
{
diff --git a/fs/btrfs/free-space-cache.h b/fs/btrfs/free-space-cache.h
index 890a8e7..45be29e 100644
--- a/fs/btrfs/free-space-cache.h
+++ b/fs/btrfs/free-space-cache.h
@@ -27,6 +27,17 @@ struct btrfs_free_space {
struct list_head list;
};
+struct inode *lookup_free_space_inode(struct btrfs_root *root,
+ struct btrfs_block_group_cache
+ *block_group, struct btrfs_path *path);
+int create_free_space_inode(struct btrfs_root *root,
+ struct btrfs_trans_handle *trans,
+ struct btrfs_block_group_cache *block_group,
+ struct btrfs_path *path);
+int btrfs_truncate_free_space_cache(struct btrfs_root *root,
+ struct btrfs_trans_handle *trans,
+ struct btrfs_path *path,
+ struct inode *inode);
int btrfs_add_free_space(struct btrfs_block_group_cache *block_group,
u64 bytenr, u64 size);
int btrfs_remove_free_space(struct btrfs_block_group_cache *block_group,
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index f08427c..16b708a 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -1700,6 +1700,7 @@ static int btrfs_finish_ordered_io(struct inode *inode,
u64 start, u64 end)
ordered_extent->len);
BUG_ON(ret);
} else {
+ BUG_ON(root == root->fs_info->tree_root);
ret = insert_reserved_file_extent(trans, inode,
ordered_extent->file_offset,
ordered_extent->start,
@@ -3197,7 +3198,7 @@ int btrfs_truncate_inode_items(struct btrfs_trans_handle
*trans,
BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
- if (root->ref_cows)
+ if (root->ref_cows || root == root->fs_info->tree_root)
btrfs_drop_extent_cache(inode, new_size & (~mask), (u64)-1, 0);
path = btrfs_alloc_path();
@@ -3345,7 +3346,8 @@ delete:
} else {
break;
}
- if (found_extent && root->ref_cows) {
+ if (found_extent && (root->ref_cows ||
+ root == root->fs_info->tree_root)) {
btrfs_set_path_blocking(path);
ret = btrfs_free_extent(trans, root, extent_start,
extent_num_bytes, 0,
@@ -3883,7 +3885,14 @@ static void inode_tree_del(struct inode *inode)
}
spin_unlock(&root->inode_lock);
- if (empty && btrfs_root_refs(&root->root_item) == 0) {
+ /*
+ * Free space cache has inodes in the tree root, but the tree root has a
+ * root_refs of 0, so this could end up dropping the tree root as a
+ * snapshot, so we need the extra !root->fs_info->tree_root check to
+ * make sure we don''t drop it.
+ */
+ if (empty && btrfs_root_refs(&root->root_item) == 0 &&
+ root != root->fs_info->tree_root) {
synchronize_srcu(&root->fs_info->subvol_srcu);
spin_lock(&root->inode_lock);
empty = RB_EMPTY_ROOT(&root->inode_tree);
@@ -4277,14 +4286,24 @@ int btrfs_write_inode(struct inode *inode, struct
writeback_control *wbc)
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_trans_handle *trans;
int ret = 0;
+ bool nolock = false;
if (BTRFS_I(inode)->dummy_inode)
return 0;
+ smp_mb();
+ nolock = (root->fs_info->closing && root ==
root->fs_info->tree_root);
+
if (wbc->sync_mode == WB_SYNC_ALL) {
- trans = btrfs_join_transaction(root, 1);
+ if (nolock)
+ trans = btrfs_join_transaction_nolock(root, 1);
+ else
+ trans = btrfs_join_transaction(root, 1);
btrfs_set_trans_block_group(trans, inode);
- ret = btrfs_commit_transaction(trans, root);
+ if (nolock)
+ ret = btrfs_end_transaction_nolock(trans, root);
+ else
+ ret = btrfs_commit_transaction(trans, root);
}
return ret;
}
@@ -6312,6 +6331,21 @@ void btrfs_destroy_inode(struct inode *inode)
spin_unlock(&root->fs_info->ordered_extent_lock);
}
+ if (root == root->fs_info->tree_root) {
+ struct btrfs_block_group_cache *block_group;
+
+ block_group = btrfs_lookup_block_group(root->fs_info,
+ BTRFS_I(inode)->block_group);
+ if (block_group && block_group->inode == inode) {
+ spin_lock(&block_group->lock);
+ block_group->inode = NULL;
+ spin_unlock(&block_group->lock);
+ btrfs_put_block_group(block_group);
+ } else if (block_group) {
+ btrfs_put_block_group(block_group);
+ }
+ }
+
spin_lock(&root->orphan_lock);
if (!list_empty(&BTRFS_I(inode)->i_orphan)) {
printk(KERN_INFO "BTRFS: inode %lu still on the orphan list\n",
@@ -6343,7 +6377,8 @@ free:
void btrfs_drop_inode(struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
- if (inode->i_nlink > 0 &&
btrfs_root_refs(&root->root_item) == 0)
+ if (inode->i_nlink > 0 &&
(btrfs_root_refs(&root->root_item) == 0 &&
+ root != root->fs_info->tree_root))
generic_delete_inode(inode);
else
generic_drop_inode(inode);
@@ -6760,27 +6795,33 @@ out_unlock:
return err;
}
-int btrfs_prealloc_file_range(struct inode *inode, int mode,
- u64 start, u64 num_bytes, u64 min_size,
- loff_t actual_len, u64 *alloc_hint)
+static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
+ u64 start, u64 num_bytes, u64 min_size,
+ loff_t actual_len, u64 *alloc_hint,
+ struct btrfs_trans_handle *trans)
{
- struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_key ins;
u64 cur_offset = start;
int ret = 0;
+ bool own_trans = true;
+ if (trans)
+ own_trans = false;
while (num_bytes > 0) {
- trans = btrfs_start_transaction(root, 3);
- if (IS_ERR(trans)) {
- ret = PTR_ERR(trans);
- break;
+ if (own_trans) {
+ trans = btrfs_start_transaction(root, 3);
+ if (IS_ERR(trans)) {
+ ret = PTR_ERR(trans);
+ break;
+ }
}
ret = btrfs_reserve_extent(trans, root, num_bytes, min_size,
0, *alloc_hint, (u64)-1, &ins, 1);
if (ret) {
- btrfs_end_transaction(trans, root);
+ if (own_trans)
+ btrfs_end_transaction(trans, root);
break;
}
@@ -6813,11 +6854,30 @@ int btrfs_prealloc_file_range(struct inode *inode, int
mode,
ret = btrfs_update_inode(trans, root, inode);
BUG_ON(ret);
- btrfs_end_transaction(trans, root);
+ if (own_trans)
+ btrfs_end_transaction(trans, root);
}
return ret;
}
+int btrfs_prealloc_file_range(struct inode *inode, int mode,
+ u64 start, u64 num_bytes, u64 min_size,
+ loff_t actual_len, u64 *alloc_hint)
+{
+ return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
+ min_size, actual_len, alloc_hint,
+ NULL);
+}
+
+int btrfs_prealloc_file_range_trans(struct inode *inode,
+ struct btrfs_trans_handle *trans, int mode,
+ u64 start, u64 num_bytes, u64 min_size,
+ loff_t actual_len, u64 *alloc_hint)
+{
+ return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
+ min_size, actual_len, alloc_hint, trans);
+}
+
static long btrfs_fallocate(struct inode *inode, int mode,
loff_t offset, loff_t len)
{
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index b37d723..af339ee 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -29,6 +29,7 @@
#include "locking.h"
#include "btrfs_inode.h"
#include "async-thread.h"
+#include "free-space-cache.h"
/*
* backref_node, mapping_node and tree_block start with this
@@ -3191,6 +3192,54 @@ static int block_use_full_backref(struct reloc_control
*rc,
return ret;
}
+static int delete_block_group_cache(struct btrfs_fs_info *fs_info,
+ struct inode *inode, u64 ino)
+{
+ struct btrfs_key key;
+ struct btrfs_path *path;
+ struct btrfs_root *root = fs_info->tree_root;
+ struct btrfs_trans_handle *trans;
+ unsigned long nr;
+ int ret = 0;
+
+ if (inode)
+ goto truncate;
+
+ key.objectid = ino;
+ key.type = BTRFS_INODE_ITEM_KEY;
+ key.offset = 0;
+
+ inode = btrfs_iget(fs_info->sb, &key, root, NULL);
+ if (!inode || IS_ERR(inode) || is_bad_inode(inode)) {
+ if (inode && !IS_ERR(inode))
+ iput(inode);
+ return -ENOENT;
+ }
+
+truncate:
+ path = btrfs_alloc_path();
+ if (!path) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ trans = btrfs_join_transaction(root, 0);
+ if (IS_ERR(trans)) {
+ btrfs_free_path(path);
+ goto out;
+ }
+
+ ret = btrfs_truncate_free_space_cache(root, trans, path, inode);
+
+ btrfs_free_path(path);
+ nr = trans->blocks_used;
+ btrfs_end_transaction(trans, root);
+ btrfs_btree_balance_dirty(root, nr);
+out:
+ iput(inode);
+ return ret;
+}
+
/*
* helper to add tree blocks for backref of type BTRFS_EXTENT_DATA_REF_KEY
* this function scans fs tree to find blocks reference the data extent
@@ -3217,15 +3266,27 @@ static int find_data_references(struct reloc_control
*rc,
int counted;
int ret;
- path = btrfs_alloc_path();
- if (!path)
- return -ENOMEM;
-
ref_root = btrfs_extent_data_ref_root(leaf, ref);
ref_objectid = btrfs_extent_data_ref_objectid(leaf, ref);
ref_offset = btrfs_extent_data_ref_offset(leaf, ref);
ref_count = btrfs_extent_data_ref_count(leaf, ref);
+ /*
+ * This is an extent belonging to the free space cache, lets just delete
+ * it and redo the search.
+ */
+ if (ref_root == BTRFS_ROOT_TREE_OBJECTID) {
+ ret = delete_block_group_cache(rc->extent_root->fs_info,
+ NULL, ref_objectid);
+ if (ret != -ENOENT)
+ return ret;
+ ret = 0;
+ }
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
root = read_fs_root(rc->extent_root->fs_info, ref_root);
if (IS_ERR(root)) {
err = PTR_ERR(root);
@@ -3860,6 +3921,8 @@ int btrfs_relocate_block_group(struct btrfs_root
*extent_root, u64 group_start)
{
struct btrfs_fs_info *fs_info = extent_root->fs_info;
struct reloc_control *rc;
+ struct inode *inode;
+ struct btrfs_path *path;
int ret;
int rw = 0;
int err = 0;
@@ -3882,6 +3945,26 @@ int btrfs_relocate_block_group(struct btrfs_root
*extent_root, u64 group_start)
rw = 1;
}
+ path = btrfs_alloc_path();
+ if (!path) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ inode = lookup_free_space_inode(fs_info->tree_root, rc->block_group,
+ path);
+ btrfs_free_path(path);
+
+ if (!IS_ERR(inode))
+ ret = delete_block_group_cache(fs_info, inode, 0);
+ else
+ ret = PTR_ERR(inode);
+
+ if (ret && ret != -ENOENT) {
+ err = ret;
+ goto out;
+ }
+
rc->data_inode = create_reloc_inode(fs_info, rc->block_group);
if (IS_ERR(rc->data_inode)) {
err = PTR_ERR(rc->data_inode);
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 859ddaa..6a625e9 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -68,7 +68,7 @@ enum {
Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd,
Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress,
Opt_compress_force, Opt_notreelog, Opt_ratio, Opt_flushoncommit,
- Opt_discard, Opt_err,
+ Opt_discard, Opt_space_cache, Opt_err,
};
static match_table_t tokens = {
@@ -92,6 +92,7 @@ static match_table_t tokens = {
{Opt_flushoncommit, "flushoncommit"},
{Opt_ratio, "metadata_ratio=%d"},
{Opt_discard, "discard"},
+ {Opt_space_cache, "space_cache"},
{Opt_err, NULL},
};
@@ -104,6 +105,8 @@ int btrfs_parse_options(struct btrfs_root *root, char
*options)
struct btrfs_fs_info *info = root->fs_info;
substring_t args[MAX_OPT_ARGS];
char *p, *num, *orig;
+ struct btrfs_super_block *disk_super;
+ u64 features;
int intarg;
int ret = 0;
@@ -235,6 +238,12 @@ int btrfs_parse_options(struct btrfs_root *root, char
*options)
case Opt_discard:
btrfs_set_opt(info->mount_opt, DISCARD);
break;
+ case Opt_space_cache:
+ disk_super = &info->super_copy;
+ features = btrfs_super_incompat_flags(disk_super);
+ features |= BTRFS_FEATURE_INCOMPAT_SPACE_CACHE;
+ btrfs_set_super_incompat_flags(disk_super, features);
+ break;
case Opt_err:
printk(KERN_INFO "btrfs: unrecognized mount option "
"''%s''\n", p);
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 66e4c66..db0da35 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -163,6 +163,7 @@ enum btrfs_trans_type {
TRANS_START,
TRANS_JOIN,
TRANS_USERSPACE,
+ TRANS_JOIN_NOLOCK,
};
static int may_wait_transaction(struct btrfs_root *root, int type)
@@ -186,7 +187,8 @@ again:
if (!h)
return ERR_PTR(-ENOMEM);
- mutex_lock(&root->fs_info->trans_mutex);
+ if (type != TRANS_JOIN_NOLOCK)
+ mutex_lock(&root->fs_info->trans_mutex);
if (may_wait_transaction(root, type))
wait_current_trans(root);
@@ -195,7 +197,8 @@ again:
cur_trans = root->fs_info->running_transaction;
cur_trans->use_count++;
- mutex_unlock(&root->fs_info->trans_mutex);
+ if (type != TRANS_JOIN_NOLOCK)
+ mutex_unlock(&root->fs_info->trans_mutex);
h->transid = cur_trans->transid;
h->transaction = cur_trans;
@@ -224,9 +227,11 @@ again:
}
}
- mutex_lock(&root->fs_info->trans_mutex);
+ if (type != TRANS_JOIN_NOLOCK)
+ mutex_lock(&root->fs_info->trans_mutex);
record_root_in_trans(h, root);
- mutex_unlock(&root->fs_info->trans_mutex);
+ if (type != TRANS_JOIN_NOLOCK)
+ mutex_unlock(&root->fs_info->trans_mutex);
if (!current->journal_info && type != TRANS_USERSPACE)
current->journal_info = h;
@@ -244,6 +249,12 @@ struct btrfs_trans_handle *btrfs_join_transaction(struct
btrfs_root *root,
return start_transaction(root, 0, TRANS_JOIN);
}
+struct btrfs_trans_handle *btrfs_join_transaction_nolock(struct btrfs_root
*root,
+ int num_blocks)
+{
+ return start_transaction(root, 0, TRANS_JOIN_NOLOCK);
+}
+
struct btrfs_trans_handle *btrfs_start_ioctl_transaction(struct btrfs_root *r,
int num_blocks)
{
@@ -348,7 +359,7 @@ int btrfs_should_end_transaction(struct btrfs_trans_handle
*trans,
}
static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
- struct btrfs_root *root, int throttle)
+ struct btrfs_root *root, int throttle, int lock)
{
struct btrfs_transaction *cur_trans = trans->transaction;
struct btrfs_fs_info *info = root->fs_info;
@@ -376,18 +387,19 @@ static int __btrfs_end_transaction(struct
btrfs_trans_handle *trans,
btrfs_trans_release_metadata(trans, root);
- if (!root->fs_info->open_ioctl_trans &&
+ if (lock && !root->fs_info->open_ioctl_trans &&
should_end_transaction(trans, root))
trans->transaction->blocked = 1;
- if (cur_trans->blocked && !cur_trans->in_commit) {
+ if (lock && cur_trans->blocked && !cur_trans->in_commit)
{
if (throttle)
return btrfs_commit_transaction(trans, root);
else
wake_up_process(info->transaction_kthread);
}
- mutex_lock(&info->trans_mutex);
+ if (lock)
+ mutex_lock(&info->trans_mutex);
WARN_ON(cur_trans != info->running_transaction);
WARN_ON(cur_trans->num_writers < 1);
cur_trans->num_writers--;
@@ -395,7 +407,8 @@ static int __btrfs_end_transaction(struct btrfs_trans_handle
*trans,
if (waitqueue_active(&cur_trans->writer_wait))
wake_up(&cur_trans->writer_wait);
put_transaction(cur_trans);
- mutex_unlock(&info->trans_mutex);
+ if (lock)
+ mutex_unlock(&info->trans_mutex);
if (current->journal_info == trans)
current->journal_info = NULL;
@@ -411,13 +424,19 @@ static int __btrfs_end_transaction(struct
btrfs_trans_handle *trans,
int btrfs_end_transaction(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
- return __btrfs_end_transaction(trans, root, 0);
+ return __btrfs_end_transaction(trans, root, 0, 1);
}
int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
- return __btrfs_end_transaction(trans, root, 1);
+ return __btrfs_end_transaction(trans, root, 1, 1);
+}
+
+int btrfs_end_transaction_nolock(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root)
+{
+ return __btrfs_end_transaction(trans, root, 0, 0);
}
/*
diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h
index e104986..15f83e1 100644
--- a/fs/btrfs/transaction.h
+++ b/fs/btrfs/transaction.h
@@ -87,10 +87,14 @@ static inline void btrfs_set_inode_last_trans(struct
btrfs_trans_handle *trans,
int btrfs_end_transaction(struct btrfs_trans_handle *trans,
struct btrfs_root *root);
+int btrfs_end_transaction_nolock(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root);
struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
int num_items);
struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root,
int num_blocks);
+struct btrfs_trans_handle *btrfs_join_transaction_nolock(struct btrfs_root
*root,
+ int num_blocks);
struct btrfs_trans_handle *btrfs_start_ioctl_transaction(struct btrfs_root *r,
int num_blocks);
int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
--
1.6.6.1
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