Core implement for inband de-duplication.
It reuse the async_cow_start() facility to do the calculate dedupe hash.
And use dedupe hash to do inband de-duplication at extent level.
The work flow is as below:
1) Run delalloc range for an inode
2) Calculate hash for the delalloc range at the unit of dedupe_bs
3) For hash match(duplicated) case, just increase source extent ref
and insert file extent.
For hash mismatch case, go through the normal cow_file_range()
fallback, and add hash into dedupe_tree.
Compress for hash miss case is not supported yet.
Current implement restore all dedupe hash in memory rb-tree, with LRU
behavior to control the limit.
Signed-off-by: Wang Xiaoguang <wangxg.f...@cn.fujitsu.com>
Signed-off-by: Qu Wenruo <quwen...@cn.fujitsu.com>
---
fs/btrfs/extent-tree.c | 20 ++++
fs/btrfs/inode.c | 253 +++++++++++++++++++++++++++++++++++++++++++------
fs/btrfs/relocation.c | 16 ++++
3 files changed, 258 insertions(+), 31 deletions(-)
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index d5691b0..3c82730 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -37,6 +37,7 @@
#include "math.h"
#include "sysfs.h"
#include "qgroup.h"
+#include "dedupe.h"
#undef SCRAMBLE_DELAYED_REFS
@@ -2399,6 +2400,8 @@ static int run_one_delayed_ref(struct btrfs_trans_handle
*trans,
if (btrfs_delayed_ref_is_head(node)) {
struct btrfs_delayed_ref_head *head;
+ struct btrfs_fs_info *fs_info = root->fs_info;
+
/*
* we've hit the end of the chain and we were supposed
* to insert this extent into the tree. But, it got
@@ -2414,6 +2417,18 @@ static int run_one_delayed_ref(struct btrfs_trans_handle
*trans,
btrfs_pin_extent(root, node->bytenr,
node->num_bytes, 1);
if (head->is_data) {
+ /*
+ * If insert_reserved is given, it means
+ * a new extent is revered, then deleted
+ * in one tran, and inc/dec get merged to 0.
+ *
+ * In this case, we need to remove its dedupe
+ * hash.
+ */
+ ret = btrfs_dedupe_del(trans, fs_info,
+ node->bytenr);
+ if (ret < 0)
+ return ret;
ret = btrfs_del_csums(trans, root,
node->bytenr,
node->num_bytes);
@@ -7087,6 +7102,11 @@ static int __btrfs_free_extent(struct btrfs_trans_handle
*trans,
btrfs_release_path(path);
if (is_data) {
+ ret = btrfs_dedupe_del(trans, info, bytenr);
+ if (ret < 0) {
+ btrfs_abort_transaction(trans, ret);
+ goto out;
+ }
ret = btrfs_del_csums(trans, root, bytenr, num_bytes);
if (ret) {
btrfs_abort_transaction(trans, ret);
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index f3ea0e0..1f384e1 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -338,6 +338,7 @@ struct async_extent {
struct page **pages;
unsigned long nr_pages;
int compress_type;
+ struct btrfs_dedupe_hash *hash;
struct list_head list;
};
@@ -349,6 +350,7 @@ struct async_cow {
u64 end;
struct list_head extents;
struct btrfs_work work;
+ enum btrfs_metadata_reserve_type reserve_type;
};
static noinline int add_async_extent(struct async_cow *cow,
@@ -356,7 +358,8 @@ static noinline int add_async_extent(struct async_cow *cow,
u64 compressed_size,
struct page **pages,
unsigned long nr_pages,
- int compress_type)
+ int compress_type,
+ struct btrfs_dedupe_hash *hash)
{
struct async_extent *async_extent;
@@ -368,6 +371,7 @@ static noinline int add_async_extent(struct async_cow *cow,
async_extent->pages = pages;
async_extent->nr_pages = nr_pages;
async_extent->compress_type = compress_type;
+ async_extent->hash = hash;
list_add_tail(&async_extent->list, &cow->extents);
return 0;
}
@@ -600,7 +604,7 @@ cont:
*/
add_async_extent(async_cow, start, num_bytes,
total_compressed, pages, nr_pages_ret,
- compress_type);
+ compress_type, NULL);
if (start + num_bytes < end) {
start += num_bytes;
@@ -646,7 +650,7 @@ cleanup_and_bail_uncompressed:
if (redirty)
extent_range_redirty_for_io(inode, start, end);
add_async_extent(async_cow, start, end - start + 1, 0, NULL, 0,
- BTRFS_COMPRESS_NONE);
+ BTRFS_COMPRESS_NONE, NULL);
*num_added += 1;
return;
@@ -675,6 +679,38 @@ static void free_async_extent_pages(struct async_extent
*async_extent)
async_extent->pages = NULL;
}
+static void end_dedupe_extent(struct inode *inode, u64 start,
+ u32 len, unsigned long page_ops)
+{
+ int i;
+ unsigned int nr_pages = len / PAGE_SIZE;
+ struct page *page;
+
+ for (i = 0; i < nr_pages; i++) {
+ page = find_get_page(inode->i_mapping,
+ start >> PAGE_SHIFT);
+ /* page should be already locked by caller */
+ if (WARN_ON(!page))
+ continue;
+
+ /* We need to do this by ourselves as we skipped IO */
+ if (page_ops & PAGE_CLEAR_DIRTY)
+ clear_page_dirty_for_io(page);
+ if (page_ops & PAGE_SET_WRITEBACK)
+ set_page_writeback(page);
+
+ end_extent_writepage(page, 0, start,
+ start + PAGE_SIZE - 1);
+ if (page_ops & PAGE_END_WRITEBACK)
+ end_page_writeback(page);
+ if (page_ops & PAGE_UNLOCK)
+ unlock_page(page);
+
+ start += PAGE_SIZE;
+ put_page(page);
+ }
+}
+
/*
* phase two of compressed writeback. This is the ordered portion
* of the code, which only gets called in the order the work was
@@ -691,6 +727,7 @@ static noinline void submit_compressed_extents(struct inode
*inode,
struct btrfs_root *root = BTRFS_I(inode)->root;
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
struct extent_io_tree *io_tree;
+ struct btrfs_dedupe_hash *hash;
int ret = 0;
again:
@@ -700,6 +737,7 @@ again:
list_del(&async_extent->list);
io_tree = &BTRFS_I(inode)->io_tree;
+ hash = async_extent->hash;
retry:
/* did the compression code fall back to uncompressed IO? */
@@ -730,7 +768,7 @@ retry:
async_extent->start +
async_extent->ram_size - 1,
&page_started, &nr_written, 0,
- NULL);
+ hash);
/* JDM XXX */
@@ -740,15 +778,26 @@ retry:
* and IO for us. Otherwise, we need to submit
* all those pages down to the drive.
*/
- if (!page_started && !ret)
- extent_write_locked_range(io_tree,
- inode, async_extent->start,
- async_extent->start +
- async_extent->ram_size - 1,
- btrfs_get_extent,
- WB_SYNC_ALL);
- else if (ret)
+ if (!page_started && !ret) {
+ /* Skip IO for dedupe async_extent */
+ if (btrfs_dedupe_hash_hit(hash))
+ end_dedupe_extent(inode,
+ async_extent->start,
+ async_extent->ram_size,
+ PAGE_CLEAR_DIRTY |
+ PAGE_SET_WRITEBACK |
+ PAGE_END_WRITEBACK |
+ PAGE_UNLOCK);
+ else
+ extent_write_locked_range(io_tree,
+ inode, async_extent->start,
+ async_extent->start +
+ async_extent->ram_size - 1,
+ btrfs_get_extent,
+ WB_SYNC_ALL);
+ } else if (ret)
unlock_page(async_cow->locked_page);
+ kfree(hash);
kfree(async_extent);
cond_resched();
continue;
@@ -878,6 +927,7 @@ retry:
free_async_extent_pages(async_extent);
}
alloc_hint = ins.objectid + ins.offset;
+ kfree(hash);
kfree(async_extent);
cond_resched();
}
@@ -897,6 +947,7 @@ out_free:
PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK |
PAGE_SET_ERROR);
free_async_extent_pages(async_extent);
+ kfree(hash);
kfree(async_extent);
goto again;
}
@@ -1011,11 +1062,17 @@ static noinline int cow_file_range(struct inode *inode,
unsigned long op;
cur_alloc_size = disk_num_bytes;
- ret = btrfs_reserve_extent(root, cur_alloc_size, cur_alloc_size,
+ if (btrfs_dedupe_hash_hit(hash)) {
+ ins.objectid = hash->bytenr;
+ ins.offset = hash->num_bytes;
+ } else {
+ ret = btrfs_reserve_extent(root, cur_alloc_size,
+ cur_alloc_size,
root->sectorsize, 0, alloc_hint,
&ins, 1, 1);
- if (ret < 0)
- goto out_unlock;
+ if (ret < 0)
+ goto out_unlock;
+ }
em = alloc_extent_map();
if (!em) {
@@ -1052,8 +1109,9 @@ static noinline int cow_file_range(struct inode *inode,
goto out_reserve;
cur_alloc_size = ins.offset;
- ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
- ram_size, cur_alloc_size, 0);
+ ret = btrfs_add_ordered_extent_dedupe(inode, start,
+ ins.objectid, cur_alloc_size, ins.offset,
+ 0, hash);
if (ret)
goto out_drop_extent_cache;
@@ -1065,7 +1123,14 @@ static noinline int cow_file_range(struct inode *inode,
goto out_drop_extent_cache;
}
- btrfs_dec_block_group_reservations(root->fs_info, ins.objectid);
+ /*
+ * Hash hit didn't allocate extent, no need to dec bg
+ * reservation.
+ * Or we will underflow reservations and block balance.
+ */
+ if (!btrfs_dedupe_hash_hit(hash))
+ btrfs_dec_block_group_reservations(root->fs_info,
+ ins.objectid);
if (disk_num_bytes < cur_alloc_size)
break;
@@ -1108,6 +1173,79 @@ out_unlock:
goto out;
}
+static int hash_file_ranges(struct inode *inode, u64 start, u64 end,
+ struct async_cow *async_cow, int *num_added)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ struct btrfs_dedupe_info *dedupe_info = fs_info->dedupe_info;
+ struct page *locked_page = async_cow->locked_page;
+ u16 hash_algo;
+ u64 dedupe_bs;
+ u64 cur_offset = start;
+ int ret = 0;
+
+ /* If dedupe is not enabled, don't split extent into dedupe_bs */
+ if (fs_info->dedupe_enabled && dedupe_info) {
+ dedupe_bs = dedupe_info->blocksize;
+ hash_algo = dedupe_info->hash_algo;
+ } else {
+ dedupe_bs = SZ_128M;
+ /* Just dummy, to avoid access NULL pointer */
+ hash_algo = BTRFS_DEDUPE_HASH_SHA256;
+ }
+
+ while (cur_offset < end) {
+ struct btrfs_dedupe_hash *hash = NULL;
+ u64 len;
+
+ len = min(end + 1 - cur_offset, dedupe_bs);
+ if (len < dedupe_bs)
+ goto next;
+
+ hash = btrfs_dedupe_alloc_hash(hash_algo);
+ if (!hash) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ ret = btrfs_dedupe_calc_hash(fs_info, inode, cur_offset, hash);
+ if (ret < 0) {
+ kfree(hash);
+ goto out;
+ }
+
+ ret = btrfs_dedupe_search(fs_info, inode, cur_offset, hash);
+ if (ret < 0) {
+ kfree(hash);
+ goto out;
+ }
+ ret = 0;
+
+next:
+ /* Redirty the locked page if it corresponds to our extent */
+ if (page_offset(locked_page) >= start &&
+ page_offset(locked_page) <= end)
+ __set_page_dirty_nobuffers(locked_page);
+
+ add_async_extent(async_cow, cur_offset, len, 0, NULL, 0,
+ BTRFS_COMPRESS_NONE, hash);
+ cur_offset += len;
+ (*num_added)++;
+ }
+out:
+ /*
+ * Caller won't unlock pages, so if error happens, we must unlock
+ * pages by ourselves.
+ */
+ if (ret)
+ extent_clear_unlock_delalloc(inode, cur_offset,
+ end, end, NULL, EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
+ EXTENT_DELALLOC | EXTENT_DEFRAG, PAGE_UNLOCK |
+ PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
+ PAGE_END_WRITEBACK | PAGE_SET_ERROR);
+ return ret;
+}
+
/*
* work queue call back to started compression on a file and pages
*/
@@ -1115,11 +1253,17 @@ static noinline void async_cow_start(struct btrfs_work
*work)
{
struct async_cow *async_cow;
int num_added = 0;
+ int ret = 0;
async_cow = container_of(work, struct async_cow, work);
- compress_file_range(async_cow->inode, async_cow->locked_page,
- async_cow->start, async_cow->end, async_cow,
- &num_added);
+ if (async_cow->reserve_type == BTRFS_RESERVE_COMPRESS)
+ compress_file_range(async_cow->inode, async_cow->locked_page,
+ async_cow->start, async_cow->end, async_cow,
+ &num_added);
+ else
+ ret = hash_file_ranges(async_cow->inode, async_cow->start,
+ async_cow->end, async_cow, &num_added);
+
if (num_added == 0) {
btrfs_add_delayed_iput(async_cow->inode);
async_cow->inode = NULL;
@@ -1169,6 +1313,8 @@ static int cow_file_range_async(struct inode *inode,
struct page *locked_page,
{
struct async_cow *async_cow;
struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ struct btrfs_dedupe_info *dedupe_info = fs_info->dedupe_info;
unsigned long nr_pages;
u64 cur_end;
int limit = 10 * SZ_1M;
@@ -1182,11 +1328,14 @@ static int cow_file_range_async(struct inode *inode,
struct page *locked_page,
async_cow->root = root;
async_cow->locked_page = locked_page;
async_cow->start = start;
+ async_cow->reserve_type = reserve_type;
if (reserve_type == BTRFS_RESERVE_COMPRESS)
cur_end = min(end, start + SZ_512K - 1);
- else
- ASSERT(0);
+ else if (fs_info->dedupe_enabled && dedupe_info) {
+ u64 len = max_t(u64, SZ_512K, dedupe_info->blocksize);
+ cur_end = min(end, start + len - 1);
+ }
async_cow->end = cur_end;
INIT_LIST_HEAD(&async_cow->extents);
@@ -1588,6 +1737,8 @@ static int run_delalloc_range(struct inode *inode, struct
page *locked_page,
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
int need_compress;
enum btrfs_metadata_reserve_type reserve_type = BTRFS_RESERVE_NORMAL;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_fs_info *fs_info = root->fs_info;
need_compress = test_range_bit(io_tree, start, end,
EXTENT_COMPRESS, 1, NULL);
@@ -1608,7 +1759,7 @@ static int run_delalloc_range(struct inode *inode, struct
page *locked_page,
ret = run_delalloc_nocow(inode, locked_page, start, end,
page_started, 0, nr_written);
- } else if (!need_compress) {
+ } else if (!need_compress && !fs_info->dedupe_enabled) {
ret = cow_file_range(inode, locked_page, start, end, end,
page_started, nr_written, 1, NULL);
} else {
@@ -2250,7 +2401,8 @@ static int insert_reserved_file_extent(struct
btrfs_trans_handle *trans,
u64 disk_bytenr, u64 disk_num_bytes,
u64 num_bytes, u64 ram_bytes,
u8 compression, u8 encryption,
- u16 other_encoding, int extent_type)
+ u16 other_encoding, int extent_type,
+ struct btrfs_dedupe_hash *hash)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_file_extent_item *fi;
@@ -2312,10 +2464,43 @@ static int insert_reserved_file_extent(struct
btrfs_trans_handle *trans,
ins.objectid = disk_bytenr;
ins.offset = disk_num_bytes;
ins.type = BTRFS_EXTENT_ITEM_KEY;
- ret = btrfs_alloc_reserved_file_extent(trans, root,
+
+ /*
+ * Only for no-dedupe or hash miss case, we need to increase
+ * extent reference
+ * For hash hit case, reference is already increased
+ */
+ if (!hash || hash->bytenr == 0)
+ ret = btrfs_alloc_reserved_file_extent(trans, root,
root->root_key.objectid,
btrfs_ino(inode), file_pos,
ram_bytes, &ins);
+ if (ret < 0)
+ goto out_qgroup;
+
+ /*
+ * Hash hit won't create a new data extent, so its reserved
+ * space won't be freed by new delayed_ref_head.
+ * Need to free it here.
+ */
+ if (btrfs_dedupe_hash_hit(hash))
+ btrfs_free_reserved_data_space(inode, file_pos, ram_bytes);
+
+ /* Add missed hash into dedupe tree */
+ if (hash && hash->bytenr == 0) {
+ hash->bytenr = ins.objectid;
+ hash->num_bytes = ins.offset;
+
+ /*
+ * Here we ignore dedupe_add error, as even it failed,
+ * it won't corrupt the filesystem. It will only only slightly
+ * reduce dedup rate
+ */
+ btrfs_dedupe_add(trans, root->fs_info, hash);
+ }
+
+out_qgroup:
+
/*
* Release the reserved range from inode dirty range map, as it is
* already moved into delayed_ref_head
@@ -3007,6 +3192,7 @@ static int btrfs_finish_ordered_io(struct
btrfs_ordered_extent *ordered_extent)
bool nolock;
bool truncated = false;
enum btrfs_metadata_reserve_type reserve_type = BTRFS_RESERVE_NORMAL;
+ int hash_hit = btrfs_dedupe_hash_hit(ordered_extent->hash);
nolock = btrfs_is_free_space_inode(inode);
@@ -3103,8 +3289,10 @@ static int btrfs_finish_ordered_io(struct
btrfs_ordered_extent *ordered_extent)
ordered_extent->disk_len,
logical_len, logical_len,
compress_type, 0, 0,
- BTRFS_FILE_EXTENT_REG);
- if (!ret)
+ BTRFS_FILE_EXTENT_REG,
+ ordered_extent->hash);
+ /* Hash hit case doesn't reserve delalloc bytes */
+ if (!ret && !hash_hit)
btrfs_release_delalloc_bytes(root,
ordered_extent->start,
ordered_extent->disk_len);
@@ -3156,15 +3344,17 @@ out:
* wrong we need to return the space for this ordered extent
* back to the allocator. We only free the extent in the
* truncated case if we didn't write out the extent at all.
+ *
+ * For hash hit case, never free that extent, as it's being used
+ * by others.
*/
- if ((ret || !logical_len) &&
+ if ((ret || !logical_len) && !hash_hit &&
!test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
!test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags))
btrfs_free_reserved_extent(root, ordered_extent->start,
ordered_extent->disk_len, 1);
}
-
/*
* This needs to be done to make sure anybody waiting knows we are done
* updating everything for this ordered extent.
@@ -10524,7 +10714,8 @@ static int __btrfs_prealloc_file_range(struct inode
*inode, int mode,
cur_offset, ins.objectid,
ins.offset, ins.offset,
ins.offset, 0, 0, 0,
- BTRFS_FILE_EXTENT_PREALLOC);
+ BTRFS_FILE_EXTENT_PREALLOC,
+ NULL);
if (ret) {
btrfs_free_reserved_extent(root, ins.objectid,
ins.offset, 0);
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index 08cfb47..972393f 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -32,6 +32,7 @@
#include "free-space-cache.h"
#include "inode-map.h"
#include "qgroup.h"
+#include "dedupe.h"
/*
* backref_node, mapping_node and tree_block start with this
@@ -4046,6 +4047,7 @@ static noinline_for_stack int relocate_block_group(struct
reloc_control *rc)
struct btrfs_trans_handle *trans = NULL;
struct btrfs_path *path;
struct btrfs_extent_item *ei;
+ struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
u64 flags;
u32 item_size;
int ret;
@@ -4168,6 +4170,20 @@ restart:
rc->search_start = key.objectid;
}
}
+ /*
+ * This data extent will be replaced, but normal dedupe_del()
+ * will only happen at run_delayed_ref() time, which is too
+ * late, so delete dedupe_hash early to prevent its ref get
+ * increased during relocation
+ */
+ if (rc->stage == MOVE_DATA_EXTENTS &&
+ (flags & BTRFS_EXTENT_FLAG_DATA)) {
+ ret = btrfs_dedupe_del(trans, fs_info, key.objectid);
+ if (ret < 0) {
+ err = ret;
+ break;
+ }
+ }
btrfs_end_transaction_throttle(trans, rc->extent_root);
btrfs_btree_balance_dirty(rc->extent_root);
--
2.10.2
--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
