| Message ID | 1452761698-17301-1-git-send-email-quwenruo@cn.fujitsu.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Jan 14, 2016 at 8:54 AM, Qu Wenruo <quwenruo@cn.fujitsu.com> wrote: > Now on-disk backend should be able to search hash now. > > Signed-off-by: Wang Xiaoguang <wangxg.fnst@cn.fujitsu.com> > Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> > --- > v4.1: > Fix a stupid typo where info->hash_type should be info->backend. > This makes on-disk backend almost unable to dedup. Having test cases (xfstests) would avoid such simple errors... wouldn't it? As in the reply I just sent for another patch: "Take a look at the good example of xfs development. For example when all the recent patches for their reflink implementation was posted (and before getting merged), a comprehensive set of test cases for xfstests was also posted..." Test cases are a good thing :) > > --- > fs/btrfs/dedup.c | 145 +++++++++++++++++++++++++++++++++++++++++++++++-------- > fs/btrfs/dedup.h | 3 ++ > 2 files changed, 127 insertions(+), 21 deletions(-) > > diff --git a/fs/btrfs/dedup.c b/fs/btrfs/dedup.c > index c97823f..bee9589 100644 > --- a/fs/btrfs/dedup.c > +++ b/fs/btrfs/dedup.c > @@ -482,6 +482,79 @@ int btrfs_dedup_disable(struct btrfs_fs_info *fs_info) > } > > /* > + * Return 0 for not found > + * Return >0 for found and set bytenr_ret > + * Return <0 for error > + */ > +static int ondisk_search_hash(struct btrfs_dedup_info *dedup_info, u8 *hash, > + u64 *bytenr_ret, u32 *num_bytes_ret) > +{ > + struct btrfs_path *path; > + struct btrfs_key key; > + struct btrfs_root *dedup_root = dedup_info->dedup_root; > + u8 *buf = NULL; > + u64 hash_key; > + int hash_len = btrfs_dedup_sizes[dedup_info->hash_type]; > + int ret; > + > + path = btrfs_alloc_path(); > + if (!path) > + return -ENOMEM; > + > + buf = kmalloc(hash_len, GFP_NOFS); > + if (!buf) { > + ret = -ENOMEM; > + goto out; > + } > + > + memcpy(&hash_key, hash + hash_len - 8, 8); > + key.objectid = hash_key; > + key.type = BTRFS_DEDUP_HASH_ITEM_KEY; > + key.offset = (u64)-1; > + > + ret = btrfs_search_slot(NULL, dedup_root, &key, path, 0, 0); > + if (ret < 0) > + goto out; > + WARN_ON(ret == 0); > + while (1) { > + struct extent_buffer *node; > + struct btrfs_dedup_hash_item *hash_item; > + int slot; > + > + ret = btrfs_previous_item(dedup_root, path, hash_key, > + BTRFS_DEDUP_HASH_ITEM_KEY); > + if (ret < 0) > + goto out; > + if (ret > 0) { > + ret = 0; > + goto out; > + } > + > + node = path->nodes[0]; > + slot = path->slots[0]; > + btrfs_item_key_to_cpu(node, &key, slot); > + > + if (key.type != BTRFS_DEDUP_HASH_ITEM_KEY || > + memcmp(&key.objectid, hash + hash_len - 8, 8)) > + break; > + hash_item = btrfs_item_ptr(node, slot, > + struct btrfs_dedup_hash_item); > + read_extent_buffer(node, buf, (unsigned long)(hash_item + 1), > + hash_len); > + if (!memcmp(buf, hash, hash_len)) { > + ret = 1; > + *bytenr_ret = key.offset; > + *num_bytes_ret = btrfs_dedup_hash_len(node, hash_item); > + break; > + } > + } > +out: > + kfree(buf); > + btrfs_free_path(path); > + return ret; > +} > + > +/* > * Caller must ensure the corresponding ref head is not being run. > */ > static struct inmem_hash * > @@ -511,7 +584,34 @@ inmem_search_hash(struct btrfs_dedup_info *dedup_info, u8 *hash) > return NULL; > } > > -static int inmem_search(struct inode *inode, u64 file_pos, > +/* Wrapper for different backends, caller needs to hold dedup_info->lock */ > +static inline int generic_search_hash(struct btrfs_dedup_info *dedup_info, > + u8 *hash, u64 *bytenr_ret, > + u32 *num_bytes_ret) > +{ > + if (dedup_info->backend == BTRFS_DEDUP_BACKEND_INMEMORY) { > + struct inmem_hash *found_hash; > + int ret; > + > + found_hash = inmem_search_hash(dedup_info, hash); > + if (found_hash) { > + ret = 1; > + *bytenr_ret = found_hash->bytenr; > + *num_bytes_ret = found_hash->num_bytes; > + } else { > + ret = 0; > + *bytenr_ret = 0; > + *num_bytes_ret = 0; > + } > + return ret; > + } else if (dedup_info->backend == BTRFS_DEDUP_BACKEND_ONDISK) { > + return ondisk_search_hash(dedup_info, hash, bytenr_ret, > + num_bytes_ret); > + } > + return -EINVAL; > +} > + > +static int generic_search(struct inode *inode, u64 file_pos, > struct btrfs_dedup_hash *hash) > { > int ret; > @@ -520,9 +620,9 @@ static int inmem_search(struct inode *inode, u64 file_pos, > struct btrfs_trans_handle *trans; > struct btrfs_delayed_ref_root *delayed_refs; > struct btrfs_delayed_ref_head *head; > - struct inmem_hash *found_hash; > struct btrfs_dedup_info *dedup_info = fs_info->dedup_info; > u64 bytenr; > + u64 tmp_bytenr; > u32 num_bytes; > > trans = btrfs_join_transaction(root); > @@ -531,14 +631,9 @@ static int inmem_search(struct inode *inode, u64 file_pos, > > again: > mutex_lock(&dedup_info->lock); > - found_hash = inmem_search_hash(dedup_info, hash->hash); > - /* If we don't find a duplicated extent, just return. */ > - if (!found_hash) { > - ret = 0; > + ret = generic_search_hash(dedup_info, hash->hash, &bytenr, &num_bytes); > + if (ret <= 0) > goto out; > - } > - bytenr = found_hash->bytenr; > - num_bytes = found_hash->num_bytes; > > delayed_refs = &trans->transaction->delayed_refs; > > @@ -574,13 +669,21 @@ again: > goto again; > > mutex_lock(&dedup_info->lock); > - /* Search again to ensure the hash is still here */ > - found_hash = inmem_search_hash(dedup_info, hash->hash); > - if (!found_hash) { > - ret = 0; > + /* > + * Search again to ensure the hash is still here and bytenr didn't > + * change > + */ > + ret = generic_search_hash(dedup_info, hash->hash, &tmp_bytenr, > + &num_bytes); > + if (ret <= 0) { > mutex_unlock(&head->mutex); > goto out; > } > + if (tmp_bytenr != bytenr) { > + mutex_unlock(&head->mutex); > + mutex_unlock(&dedup_info->lock); > + goto again; > + } > hash->bytenr = bytenr; > hash->num_bytes = num_bytes; > > @@ -609,15 +712,15 @@ int btrfs_dedup_search(struct inode *inode, u64 file_pos, > if (WARN_ON(!dedup_info || !hash)) > return 0; > > - if (dedup_info->backend == BTRFS_DEDUP_BACKEND_INMEMORY) > - ret = inmem_search(inode, file_pos, hash); > - > - /* It's possible hash->bytenr/num_bytenr already changed */ > - if (ret == 0) { > - hash->num_bytes = 0; > - hash->bytenr = 0; > + if (dedup_info->backend < BTRFS_DEDUP_BACKEND_LAST) { > + ret = generic_search(inode, file_pos, hash); > + if (ret == 0) { > + hash->num_bytes = 0; > + hash->bytenr = 0; > + } > + return ret; > } > - return ret; > + return -EINVAL; > } > > static int hash_data(struct btrfs_dedup_info *dedup_info, const char *data, > diff --git a/fs/btrfs/dedup.h b/fs/btrfs/dedup.h > index f23053c..3c08b86 100644 > --- a/fs/btrfs/dedup.h > +++ b/fs/btrfs/dedup.h > @@ -137,6 +137,9 @@ int btrfs_dedup_calc_hash(struct btrfs_root *root, struct inode *inode, > * *INCREASED*, and hash->bytenr/num_bytes will record the existing > * extent data. > * Return 0 for a hash miss. Nothing is done > + * Return <0 for error. > + * > + * Only on-disk backedn may return error though. > */ > int btrfs_dedup_search(struct inode *inode, u64 file_pos, > struct btrfs_dedup_hash *hash); > -- > 2.7.0 > > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/btrfs/dedup.c b/fs/btrfs/dedup.c index c97823f..bee9589 100644 --- a/fs/btrfs/dedup.c +++ b/fs/btrfs/dedup.c @@ -482,6 +482,79 @@ int btrfs_dedup_disable(struct btrfs_fs_info *fs_info) } /* + * Return 0 for not found + * Return >0 for found and set bytenr_ret + * Return <0 for error + */ +static int ondisk_search_hash(struct btrfs_dedup_info *dedup_info, u8 *hash, + u64 *bytenr_ret, u32 *num_bytes_ret) +{ + struct btrfs_path *path; + struct btrfs_key key; + struct btrfs_root *dedup_root = dedup_info->dedup_root; + u8 *buf = NULL; + u64 hash_key; + int hash_len = btrfs_dedup_sizes[dedup_info->hash_type]; + int ret; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + buf = kmalloc(hash_len, GFP_NOFS); + if (!buf) { + ret = -ENOMEM; + goto out; + } + + memcpy(&hash_key, hash + hash_len - 8, 8); + key.objectid = hash_key; + key.type = BTRFS_DEDUP_HASH_ITEM_KEY; + key.offset = (u64)-1; + + ret = btrfs_search_slot(NULL, dedup_root, &key, path, 0, 0); + if (ret < 0) + goto out; + WARN_ON(ret == 0); + while (1) { + struct extent_buffer *node; + struct btrfs_dedup_hash_item *hash_item; + int slot; + + ret = btrfs_previous_item(dedup_root, path, hash_key, + BTRFS_DEDUP_HASH_ITEM_KEY); + if (ret < 0) + goto out; + if (ret > 0) { + ret = 0; + goto out; + } + + node = path->nodes[0]; + slot = path->slots[0]; + btrfs_item_key_to_cpu(node, &key, slot); + + if (key.type != BTRFS_DEDUP_HASH_ITEM_KEY || + memcmp(&key.objectid, hash + hash_len - 8, 8)) + break; + hash_item = btrfs_item_ptr(node, slot, + struct btrfs_dedup_hash_item); + read_extent_buffer(node, buf, (unsigned long)(hash_item + 1), + hash_len); + if (!memcmp(buf, hash, hash_len)) { + ret = 1; + *bytenr_ret = key.offset; + *num_bytes_ret = btrfs_dedup_hash_len(node, hash_item); + break; + } + } +out: + kfree(buf); + btrfs_free_path(path); + return ret; +} + +/* * Caller must ensure the corresponding ref head is not being run. */ static struct inmem_hash * @@ -511,7 +584,34 @@ inmem_search_hash(struct btrfs_dedup_info *dedup_info, u8 *hash) return NULL; } -static int inmem_search(struct inode *inode, u64 file_pos, +/* Wrapper for different backends, caller needs to hold dedup_info->lock */ +static inline int generic_search_hash(struct btrfs_dedup_info *dedup_info, + u8 *hash, u64 *bytenr_ret, + u32 *num_bytes_ret) +{ + if (dedup_info->backend == BTRFS_DEDUP_BACKEND_INMEMORY) { + struct inmem_hash *found_hash; + int ret; + + found_hash = inmem_search_hash(dedup_info, hash); + if (found_hash) { + ret = 1; + *bytenr_ret = found_hash->bytenr; + *num_bytes_ret = found_hash->num_bytes; + } else { + ret = 0; + *bytenr_ret = 0; + *num_bytes_ret = 0; + } + return ret; + } else if (dedup_info->backend == BTRFS_DEDUP_BACKEND_ONDISK) { + return ondisk_search_hash(dedup_info, hash, bytenr_ret, + num_bytes_ret); + } + return -EINVAL; +} + +static int generic_search(struct inode *inode, u64 file_pos, struct btrfs_dedup_hash *hash) { int ret; @@ -520,9 +620,9 @@ static int inmem_search(struct inode *inode, u64 file_pos, struct btrfs_trans_handle *trans; struct btrfs_delayed_ref_root *delayed_refs; struct btrfs_delayed_ref_head *head; - struct inmem_hash *found_hash; struct btrfs_dedup_info *dedup_info = fs_info->dedup_info; u64 bytenr; + u64 tmp_bytenr; u32 num_bytes; trans = btrfs_join_transaction(root); @@ -531,14 +631,9 @@ static int inmem_search(struct inode *inode, u64 file_pos, again: mutex_lock(&dedup_info->lock); - found_hash = inmem_search_hash(dedup_info, hash->hash); - /* If we don't find a duplicated extent, just return. */ - if (!found_hash) { - ret = 0; + ret = generic_search_hash(dedup_info, hash->hash, &bytenr, &num_bytes); + if (ret <= 0) goto out; - } - bytenr = found_hash->bytenr; - num_bytes = found_hash->num_bytes; delayed_refs = &trans->transaction->delayed_refs; @@ -574,13 +669,21 @@ again: goto again; mutex_lock(&dedup_info->lock); - /* Search again to ensure the hash is still here */ - found_hash = inmem_search_hash(dedup_info, hash->hash); - if (!found_hash) { - ret = 0; + /* + * Search again to ensure the hash is still here and bytenr didn't + * change + */ + ret = generic_search_hash(dedup_info, hash->hash, &tmp_bytenr, + &num_bytes); + if (ret <= 0) { mutex_unlock(&head->mutex); goto out; } + if (tmp_bytenr != bytenr) { + mutex_unlock(&head->mutex); + mutex_unlock(&dedup_info->lock); + goto again; + } hash->bytenr = bytenr; hash->num_bytes = num_bytes; @@ -609,15 +712,15 @@ int btrfs_dedup_search(struct inode *inode, u64 file_pos, if (WARN_ON(!dedup_info || !hash)) return 0; - if (dedup_info->backend == BTRFS_DEDUP_BACKEND_INMEMORY) - ret = inmem_search(inode, file_pos, hash); - - /* It's possible hash->bytenr/num_bytenr already changed */ - if (ret == 0) { - hash->num_bytes = 0; - hash->bytenr = 0; + if (dedup_info->backend < BTRFS_DEDUP_BACKEND_LAST) { + ret = generic_search(inode, file_pos, hash); + if (ret == 0) { + hash->num_bytes = 0; + hash->bytenr = 0; + } + return ret; } - return ret; + return -EINVAL; } static int hash_data(struct btrfs_dedup_info *dedup_info, const char *data, diff --git a/fs/btrfs/dedup.h b/fs/btrfs/dedup.h index f23053c..3c08b86 100644 --- a/fs/btrfs/dedup.h +++ b/fs/btrfs/dedup.h @@ -137,6 +137,9 @@ int btrfs_dedup_calc_hash(struct btrfs_root *root, struct inode *inode, * *INCREASED*, and hash->bytenr/num_bytes will record the existing * extent data. * Return 0 for a hash miss. Nothing is done + * Return <0 for error. + * + * Only on-disk backedn may return error though. */ int btrfs_dedup_search(struct inode *inode, u64 file_pos, struct btrfs_dedup_hash *hash);